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Data Flow System
Document Title: Document Number: Issue: Date: VISTA Data Reduction Library Design VIS-SPE-IOA-20000-0010 1.6 2006-12-20

Document Prepared by: Document Approved by: Document Reviewed by: Document Released by:

Jim Lewis Peter Bunclark Simon Hodgkin (CASU) Mike Irwin (CASU Manager) Will Sutherland (Project Scientist) Malcolm Stewart (VDFS Manager)

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Change Record
Issue 1.0 1.1 1.2 1.3 1.4 1.5 1.6 Date 2004-12-17 2005-05-03 2005-08-12 2005-12-25 2006-06-15 2006-09-28 2006-12-20 Sections Affected All All 4 All All 0,5,6,7 2,6,8 Reason/Initiation/Documents/Remarks New Document post-FDR revision post DICB comments Consistency with DRL v0.1, JRL, MJI, PSB updates Many changes to all sections to help bring the document into line with DRL 0.3 Explanations of dummy products expanded. Expanded list of fatal and non-fatal errors for recipes. Many other smaller changes Added vircam_destripe + description Added parameters to jitter_microstep_process. Many other smaller changes, including touchups to table 10-1 update QC & DRS dictionaries Update vircam_standard_process, modify vircam_jitter_microstep_process, and modify entries in table 10-1. Modified vircam_illum entry in chapter 6. Modified vircam_mesostep_analyse and vircam_defringe Spell check and added QC STRIPERMS

Notification List
The following people should be notified by email that a new issue of this document is available. IoA RAL QMC Will Sutherland Gavin Dalton Jim Emerson


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Change Record ............................................................................................................... 2 Notification List ............................................................................................................. 2 Figures............................................................................................................................ 6 Tables ............................................................................................................................. 6 1 Introduction ............................................................................................................ 7 1.1 Scope .............................................................................................................. 7 1.2 Applicable Documents ................................................................................... 7 1.3 Reference Documents .................................................................................... 7 1.4 Abbreviations and Acronyms ........................................................................ 8 1.5 Glossary ......................................................................................................... 8 2 Mathematical Description .................................................................................... 10 2.1 Reset Correction........................................................................................... 10 2.2 Non-Linearity ............................................................................................... 10 2.3 Gain Correction ............................................................................................ 13 2.4 Measurement of Read Noise and Gain ........................................................ 13 2.5 Dark-correction, flat-fielding and sky-correction ........................................ 14 2.6 Stripe Removal............................................................................................. 15 2.7 Fringe Removal ............................................................................................ 15 2.8 Image persistence ......................................................................................... 16 2.9 Crosstalk ...................................................................................................... 16 2.10 Astrometric Calibration ............................................................................... 17 2.11 World Coordinate System ............................................................................ 18 2.12 Effect of Scale Change on Photometry ........................................................ 18 2.13 Confidence Maps ......................................................................................... 18 2.14 Catalogue generation ................................................................................... 20 2.15 Photometric Zeropoint ................................................................................. 22 2.16 Illumination Correction ................................................................................ 23 3 Functional Description ......................................................................................... 25 3.1 Recipes ......................................................................................................... 26 4 Instrument Data Description ................................................................................ 37 5 DRL Data Structures ............................................................................................ 43 5.1 Introduction to Data Products ...................................................................... 43 5.2 Channel Table .............................................................................................. 45 5.3 Bad Pixel Mask ............................................................................................ 46 5.4 Confidence Maps ......................................................................................... 46 5.5 Dark Current Image ..................................................................................... 47 5.6 Crosstalk Matrix........................................................................................... 47 5.7 Illumination Correction Table...................................................................... 47 5.8 Difference/Ratio Images .............................................................................. 48 5.9 Difference/Ratio Image Statistics Tables..................................................... 48 5.10 Persistence Mask Table................................................................................ 48 5.11 Standards Table ............................................................................................ 49 5.12 Object Catalogues ........................................................................................ 49 5.13 Matched Standards Table ............................................................................. 51 5.14 Readnoise/Gain File ..................................................................................... 51


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5.15 Photometric Calibration Table ..................................................................... 52 DRL Functions ..................................................................................................... 54 6.1 vircam_crosstalk .......................................................................................... 55 6.2 vircam_darkcor ............................................................................................ 56 6.3 vircam_defringe ........................................................................................... 57 6.4 vircam_destripe ............................................................................................ 59 6.5 vircam_flatcor .............................................................................................. 60 6.6 vircam_genlincur ......................................................................................... 61 6.7 vircam_getstds ............................................................................................. 62 6.8 vircam_illum ................................................................................................ 64 6.9 vircam_imcombine ...................................................................................... 66 6.10 vircam_imcore ............................................................................................. 67 6.11 vircam_imdither ........................................................................................... 69 6.12 vircam_interleave ......................................................................................... 71 6.13 vircam_lincor ............................................................................................... 73 6.14 vircam_matchstds ........................................................................................ 74 6.15 vircam_matchxy ........................................................................................... 76 6.16 vircam_mkconf ............................................................................................ 77 6.17 vircam_persist .............................................................................................. 78 6.18 vircam_photcal ............................................................................................. 80 6.19 vircam_platesol ............................................................................................ 82 7 Data Reduction CPL Plugins ............................................................................... 85 7.1 vircam_reset_combine ................................................................................. 85 7.2 vircam_dark_combine.................................................................................. 87 7.3 vircam_dark_current .................................................................................... 89 7.4 vircam_dome_flat_combine ........................................................................ 90 7.5 vircam_detector_noise ................................................................................. 92 7.6 vircam_linearity_analyse ............................................................................. 93 7.7 vircam_twilight_flat_combine ..................................................................... 94 7.8 vircam_mesostep_analyse............................................................................ 97 7.9 vircam_persistence_analyse ......................................................................... 98 7.10 vircam_crosstalk_analyse ............................................................................ 99 7.11 vircam_jitter_microstep_process ............................................................... 100 7.12 vircam_standard_process ........................................................................... 103 8 Validation tests................................................................................................... 107 8.1 vircam_darkcor .......................................................................................... 107 8.2 vircam_destripe .......................................................................................... 108 8.3 vircam_flatcor ............................................................................................ 108 8.4 vircam_getstds ........................................................................................... 108 8.5 vircam_imcombine .................................................................................... 108 8.6 vircam_imcore ........................................................................................... 109 8.7 vircam_imdither ......................................................................................... 110 8.8 vircam_interleave ....................................................................................... 110 8.9 vircam_lincor ............................................................................................. 110 8.10 vircam_matchstds ...................................................................................... 111 8.11 vircam_matchxy ......................................................................................... 111 8.12 vircam_mkconf .......................................................................................... 111 8.13 vircam_platesol .......................................................................................... 111


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8.14 Validation Test Data .................................................................................. Development Plan .............................................................................................. Appendix: QC1 Parameters ............................................................................... Appendix: DRS Dictionary ................................................................................ Appendix: Raw FITS Header.............................................................................


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Figure 3-1 Relationship between recipes, calibration data and data products. ............ 25 Figure 3-2 Bootstrapping table relating Calibration Observations, Recipes and Calibration Products............................................................................................. 26 Figure 3-3 vircam_reset_combine ............................................................................... 27 Figure 3-4 vircam_dark_combine ................................................................................ 27 Figure 3-5 vircam_badpix_mask ................................................................................. 28 Figure 3-6 vircam_dome_flat_combine ....................................................................... 28 Figure 3-7 vircam_detector_noise ............................................................................... 29 Figure 3-8 vircam_linearity_analyse ........................................................................... 29 Figure 3-9 vircam_twilight_combine .......................................................................... 30 Figure 3-10 vircam_illumination_analyse ................................................................... 31 Figure 3-11 vircam_mesotep_analyse ......................................................................... 32 Figure 3-12 vircam_persistence_analyse ..................................................................... 33 Figure 3-13 vircam_crosstalk_analyse ........................................................................ 34 Figure 3-14 vircam_sky_flat_combine ........................................................................ 35 Figure 3-15 vircam_jitter_microstep_process ............................................................. 36 Figure 4-1 A VIRCAM engineering readout shown displayed in the ESO-VLT RealTime Display Tool ............................................................................................... 37 Figure 4-2 Synthetic VISTA data shown organised by GASGANO ........................... 39

Tables
Table Table Table Table Table Table Table 4-1 Data Processing Table ................................................................................. 42 5-1 DO and PRO categories for data products .................................................. 45 8-1 Description of test data files ..................................................................... 113 8-2 Files to be used to test each vircam function ............................................. 114 8-3 Files to use in testing each vircam plugin ................................................. 115 9-1 Development Schedule .............................................................................. 116 10-1 The origin of QC Parameters ................................................................... 127


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Introduction

This document forms part of the package of documents for the design of the Data Flow System for VISTA, the Visible and Infra-Red Survey Telescope for Astronomy.

1.1 Scope
This document describes the VISTA Infra-Red Camera Data Reduction Library Design for the output from the 16 Raytheon VIRGO IR detectors in the Infra RedCamera for VISTA (VIRCAM). The baseline requirements for calibration are included in the VISTA Infra-Red Camera Data Flow System User Requirements [AD2], and the Calibration Plan is described in [AD3].

1.2 Applicable Documents
[AD1] Data Flow for the VLT/VLTI Instruments Deliverables Specification, VLTSPE-ESO-19000-1618, issue 2.0, 2004-05-22. [AD2] VISTA Infra Red Camera DFS Impact, VIS-SPE-IOA-20000-00001, issue 1.3, 2005-12-25. [AD3] VISTA Infra Red Camera DFS Calibration Plan, VIS-SPE-IOA-20000-00002, issue 1.3, 2005-12-25. [AD4] VISTA Infra Red Camera DFS Data Reduction Library Specification, VISSPE-IOA-20000-00003, issue 1.0, 2005-02-08. [AD5] Data Interface Control Document, GEN-SPE-ESO-19940-0794, issue 3, 2005-02-01. [AD6] Common Pipeline Library User Manual, VLT-MAN-ESO-19500-2720, issue 2.0.1, 2005-04-14 [AD7] Common Pipeline Library Reference Manual, VLT-MAN-ESO-19500-2721, issue 2.0, 2005-04-08

1.3 Reference Documents
[RD 1] VISTA IR Camera Software Functional Specification, VIS-DES-ATC-0608100001, issue 2.0, 2003-11-12. [RD 2] IR Camera Observation Software Design Description, VIS-DES-ATC-060840001, issue 3.2 2005-02-24. [RD 3] VISTA Science Requirements Document, VIS-SPE-VSC-00000-0001, issue 2.0, 2000-10-26 [RD 4] Overview of VISTA IR Camera Data Interface Dictionaries, VIS-SPE-IOA20000-0004, 0.1, 2003-11-13 [RD 5] Definition of the Flexible Image Transport System (FITS), NOST 100-2.0 [RD 6] The FITS image extension, Ponz et al, Astron. Astrophys. Suppl. Ser. 105, 5355, 1994 [RD 7] Representations of world coordinates in FITS, Griesen, & Calabretta, A&A, 395, 1061.2002 [RD 8] Representations of celestial coordinates in FITS, Calabretta & Griesen, A&A, 395, 1077, 2002


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[RD 9] Detectors and Data Analysis Techniques for Wide Field Optical Imaging, Irwin M.J., 1996, Instrumentation for Large Telescopes, VII Canary Islands Winter School, eds. J.M. RodrМguez Espinosa, A. Herrero, F. SАnchez, p35. Also available from http://www.ast.cam.ac.uk/~mike/processing.ps.gz [RD 10] INT WFS pipeline processing, Irwin M and Lewis J, New Astronomy Reviews, 45, Issue 1-2, p105, 2001. [RD 11] VISTA Data Flow System: pipeline processing for WFCAM and VISTA, Irwin et al, Ground-based telescopes, ed. Oschmann, proc SPIE, 5493, p411, 2004 [RD 12] Automatic analysis of crowded fields, Irwin M. 1985 MNRAS 214,575 [RD 13] Understanding Robust and Exploratory Data Analysis, Hoaglin, Mosteller & Tukey 1983, Wiley. [RD 14] Analysis of astronomical images using moments, Stobie R, British Interplanetary Journal (Image Processing), 33, p323, 1980

1.4 Abbreviations and Acronyms
2MASS ADU CDS DFS DIT FITS FWHM HOWFS LUT MAD MEF NDR RHS RRR VDFS VIRCAM VISTA WCS WFCAM 2 Micron All Sky Survey Analogue to Digital Unit Correlated Double Sampling Data Flow System Digital Integration Flexible Image Transport System Full Width at Half Maximum High-Order Wavefront Sensor Look Up Table Median Absolute Deviation from median Multi-Extension FITS Non-Destructive Read Right Hand Side Reset-Read-Read mode VISTA Data Flow System VISTA Infra Red Camera Visible and Infrared Survey Telescope for Astronomy World Coordinate System Wide Field Camera (on UKIRT)

1.5 Glossary
CDS Correlated-Double Sampling; before the charge of each pixel is transferred to the output node of the detector, the output node is reset to a reference value. The pixel charge is then transferred to the output node. The final value of the charge assigned to this pixel is the difference between the reference value and the transferred charge. An integer array, normalised to a median of 100%, which is associated with an image. Combined with an estimate of the

Confidence Map


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DAS DIT Exposure Integration Jitter (pattern)

Mesostep Microstep (pattern)

OB Object Pawprint

Preset Robust Estimate Tile

sky background variance of the image, it assigns a relative weight to each pixel in the image and automatically factors in an exposure map. Bad pixels are assigned a value of 0. It is especially important in image filtering, mosaicing and stacking. Data Acquisition System Digital Integrations mean that separate readouts are summed digitally. The stored product of many individual integrations that have been co-added in the DAS. The sum of the integration times is the exposure time. A simple snapshot, within the DAS, of a specified elapsed time. This elapsed time is known as the integration time. A pattern of exposures at positions each shifted by a small movement (<30 arcsec) from the reference position. Unlike a microstep the non-integral part of the shifts is any fractional number of pixels. Each position of a jitter pattern can contain a microstep pattern. A sequence of exposures designed to completely sample across the face of the detectors in medium-sized steps, in order to monitor residual systematics in the photometry. A pattern of exposures at positions each shifted by a very small movement (<3 arcsec) from the reference position. Unlike a jitter the non-integral part of the shifts are exact fractions of a pixel, which allows the pixels in the series to be interlaced in an effort to increase resolution. A microstep pattern can be contained within each position of a jitter pattern. Observation Block In the context of image analysis, an astronomical object. 16 non-contiguous images of the sky produced by VIRCAM with its 16 non-contiguous chips (see Fig 2-2 of [AD3]). The name is from the similarity to the prints made by the padded paw of an animal (the terminology was more appropriate to 4-chip cameras). A telescope slew to a new position requiring a reconfiguration of various telescope systems. A statistical estimator that is resilient to small perturbations on the assumed shape of the underlying distribution. A filled area of sky fully sampled (filling in the gaps in a pawprint) by combining multiple pawprints. Because of the detector spacing the minimum number of pointed observations (with fixed offsets) required for reasonably uniform coverage is 6, which would expose each piece of sky, away from the edges of the tile, to at least 2 camera pixels. The pipeline does not combine pawprints into tiles.


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Mathematical Description

In this section we include a mathematic description of some of the methods we will use to calibrate and correct data from VIRCAM. The main technical challenges in processing VISTA data stem from the fact that: IR detectors are currently inherently more unstable than their optical counterparts; the sky emission, roughly 100 times brighter than most objects of interest, varies in a complex spatial and temporal manner; and the large data volume that arises from NIR mosaic cameras. To minimise the subsequent data volume several basic pre-processing steps will be carried out in the VISTA data-acquisition system, including reset-correction and co-addition of successive DITs from the same exposure. The first stage of the VDFS pipeline will be to apply a linearity correction as outlined in section 2.2. Subsequent processing steps including: dark and reset-anomaly correction; flat-fielding and inter-channel gain correction; and sky artefact removal (e.g. fringe patterns), are designed to remove the instrumental and residual sky signatures from the images. The algorithms used in the VIRCAM pipeline are the result of 25 years development in the analysis of digital images. An excellent and detailed review of the mathematical techniques involved in wide-field image analysis is given in [RD 9]. In particular, the robust estimator is detailed and an in-depth description of image detection and parameterization, as used in section 2.14, is given. Several of the effects included in this section may not even exist in VIRCAM data; it is prudent however to make arrangements for dealing with such issues if early experience with the data shows the effects to be present. We outline in the following sections the salient points of the mathematical operations to be performed, for further detail see [AD2], [AD3] and [AD4].

2.1 Reset Correction
As with most electronic detectors infrared detectors are given a pedestal bias level by the driving electronics. As such the first step in any reduction of such data is to remove that bias. For VIRCAM this will be done in the DAS. This removes the need for explicit bias removal in the pipeline.

2.2 Non-Linearity
The Calibration Plan [AD3] lays out the necessity and the methodology for calibrating and correcting for the expected non-linearity in the response of the detector system to incident radiation. 2.2.1 Correcting for non-linearity In default CDS reset-read-read (RRR) mode, downstream of the data acquisition system (DAS) the output that we see is
I = I 2 - I 1 = f ( I 2 ) - f ( I 1 )
(2-1)


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where I1 and I 2 denote the non-linear first (i.e. the reset-frame) and second readouts respectively and I1 and I 2 the desired linear quantities. The non-linear function f(I) maps the distortion of the desired linear counts to the non-linear system I . If we define the inverse transform g( I ) that maps measured counts I to linearized counts I as the inverse operator g() = f -1() then I = g ( I ) and I 1 = g ( I 1 ) I 2 = g ( I 2 )
(2-2)

If I1 and I 2 were directly available this is a one-to-one mapping and can be done efficiently and accurately using Look Up Tables (LUT). This is the conventional way of implementing the correction prior to other image manipulation operations. However, if I1 and I 2 are not separately available and all we have to work from is the difference I then a simple LUT transformation is not possible.

For example, taking the simplest case where the illumination level across the detector has not changed during the course of the RRR and no on-board co-addition is happening then, in principle given only I and knowledge of the timing of the RRR operations we can deduce I1 and I 2 by using the effective integration time for each to estimate their scaling to the measured difference I such that,
I 1 = kI and I 2 = (1 + k )I
(2-3)

Unfortunately, the ratio k will not be constant for the non-linear quantities I1 and I 2 forcing us to adopt a scheme along the following lines.

Given I and defining the non-linear operator f () as a polynomial with coefficients am (typically up to quartic) we have
I =


m

am ( I

m 2

- I1 ) =

m


m

a m [(1 + k ) m I m - k m I m ]

(2-4)

The quantity we want I is buried in the non-linearity of the RHS and we have to solve an equation like this for every pixel. This is possible, and relatively simple to program using something like a Gauss-Seidel iterative scheme, but is more inefficient than a direct mapping. If we wanted to use a completely general LUT approach we would require a 2D LUT for all possible values of I1 and I 2 i.e. 65k в 65k in size, or 4.3 в 2 Gbytes. Most likely we would need a different correction for each "channel" making a total of 256 в 8.6 Gbytes = 2.2 Tbytes of LUT for the VIRCAM! Of course if the range of values of k is limited via exposure time quantisation this decreases the size of the total number


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of LUTs required considerably for the constant illumination case, but would be an ugly and possibly impractical solution. Practical considerations (e.g. data volume), suggest two alternative solutions for nonlinearity correction: either correct the individual frames directly in the DAS by measuring and downloading the appropriate LUTs, or polynomial coefficients, to the DAS; or use a non-linear inversion on the reset-corrected frames as outlined here. This methodology is not generally applicable, e.g. to multi-NDR/gradient fitting readouts, but is directly applicable to co-added (or co-averaged) frames of the same exposure times, assuming constant illumination over the series. For reset-corrected data, the non-linear inversion is competitive with complex operations on LUTs and much simpler to implement. It also has the added advantage of removing all aspects of the non-linearity correction from the DAS. The main disadvantages are the method is restricted to CDS RRR mode, and if the illumination level is rapidly varying (e.g. twilight) the effective scale factors ki may be hard to compute accurately - although for all realistic practical situations the knock-on effect is likely to be negligible.
2.2.2 Measuring non-linearity If all that is available are reset-corrected data from say a time series of dome flats, it is still feasible to directly compute the non-linearity coefficients.

Given a series of measurements {i} of I i and using the previous notation and polynomial model
I i =


m

am ( I

m 2

- I1 ) =

m


m

a m I i [(1 + k i ) m - k i ]

m

m

(2-5)

where k i are the exposure ratios under the constant illumination. In general I i = st i where ti is the exposure time of the ith reset-corrected frame in the series and s is a fixed (for the series) unknown scale factor. The k i are computable from a knowledge of the exposure times and the reset-read overhead, ti and I i are measured quantities leaving the polynomial coefficients am and the scaling s to be determined. Thus the model is defined by

I i =


m

am ( I

m 2

- I1 ) -

m


m

a m s m t i [(1 + k i ) m - k i ]

m

m

(2-6)

and can be readily solved by standard linear least-squares methods using the following sleight-of-hand. Since the scaling s and hence the polynomial solution am are coupled, by simply (and logically) requiring in the final solution a1 = 1 , computation of s can be completely avoided.


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Rewriting the previous equation in the following form makes this more apparent I i =


m

(a m s m )t im [(1 + k i ) m - k im ] =


m

bm t im [(1 + k i ) m - k im ]

(2-7)

where now bm are the coefficients to be solved for. The final step is to note that

a m = bm / s m = bm / b1m since by definition a1 = 1 .

(2-8)

2.3 Gain Correction
In the case of a single detector camera the mean flat field image is normalised to a value of 1. This ensures that when the flat field correction is done the average counts in the output image is the same as in the input. For multi-detector instruments, we normalise the mean flat field image for each detector by: V= where I
i


i =1

n

I

i

N

(2-9)

is a robust estimate of the average flux in the combined flat field image for

the ith detector. Normalising in this way ensures that when doing flat field correction we also include a factor that removes the differences in mean gain of each detector.

2.4 Measurement of Read Noise and Gain
The read noise and gain can be measured illumination and two similarly observed (in dark frames. Forming the difference of the difference frame 2 . Doing the same for f using two dome flat terms of exposure and two flat frames gives the two dark frames frames of integration a variance 2 yields d .
d2

similar times) for the If the

background means of the flat and dark frames are: m f 1 , m f 2 and md 1 , m gain in electrons per ADU is:
2 = (( m f 1 + m f 2 ) - ( md 1 + md 2 )) /( 2 - d ) f

the local

(2-10)

and the readout noise in electrons is



ro

= d / 2

(2-11)


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2.5 Dark-correction, flat-fielding and sky-correction
If the fringe spatial pattern is stable and if flat fields can be generated without fringing present, it is possible to decouple sky correction and fringe correction and apply a defringing method similar to the one we have developed for optical imaging [RD 11]. This involves creating a series of master fringe frames which are scaled by a suitable factor for each object frame. The scale factors are adjusted to minimise the fringe pattern in the processed frame. Standard NIR processing recipes often subtract sky first and then flat-field. We can see why this can be advantageous compared with dark-correcting, flat-fielding and sky-correcting by considering the following encapsulation of the problem
D ( x, y ) = ff ( x, y )[S ( x, y ) + F ( x, y ) + O( x, y ) + T ( x, y )] + dc( x, y )
(2-12)

where D( x, y illumination, T ( x, y ) is the generality we

) is observed, ff ( x, y ) is the flat-field function, S ( x, y ) is the sky F ( x, y ) is the fringe contribution, O( x, y ) is the object contribution, thermal contribution, dc( x, y ) is the dark current, and without loss of have excluded any explicit wavelength and time-dependence for clarity.

Stacking a series of dithered object frames with rejection produces an estimate of the terms ^ I ( x, y ) = ff ( x, y )[S ( x, y ) + F ( x, y ) + T ( x, y )] + dc( x, y ) therefore,
^ D( x, y ) - I ( x, y ) = ff ( x, y )O( x, y )
(2-14) (2-13)

obviating the need for dark-correcting and fringe removal as both separate data gathering requirements and as separate data processing steps; and minimising the effect of systematic and random errors in the flat-field function by removing the largest potential error terms. In the event that the dark correction stage fails to remove the reset anomaly completely, the residual background variation is analogous to the problem of dealing with short-term variations in sky structure and can be dealt with using the methodology above. The caveats here of course are that this method may well remove parts of large extended objects, large area nebulosity, and large low surface brightness objects and so on, unless suitable offset skies are used in the sky frame construction. Unfortunately this then opens the door for spatial and temporal variability of the sky background, leaving residual patterns. The optimal strategy to use depends on the stability of the flat-fields, and the time constants for sky fringe pattern variations, and will be dealt with by assessing these characteristics during commissioning and then invoking suitable processing recipes.


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The alternative is to treat the dark correction dc( x, y ) , flat field ff ( x, y ) , and fringe pattern F ( x, y ) , as accurately known master library frames, in which case data processing involves solving the following variant of the problem

D(x, y) = f f (x, y) [S(x, y) + k.F (x, y) + O(x, y) + T (x, y)] + dc(x, y) (2-15)
where k is a scale factor to be determined by the fringe-removing algorithm. In this case applying the master frames leads to D (x, y) = S(x, y) + O(x, y) + T (x, y)
(2-16)

reducing the problem to one of detecting astronomical objects on an additive, slowly spatially varying, background. This could be the method of choice for analysing large scale astronomical surface brightness variations.

2.6 Stripe Removal
AIT data from the VIRCAM detectors has shown a low level medium frequency stripe pattern. The stripes are perpendicular to the readout direction and are the same for all channels in a detector. This means that they can be modelled out by calculating the median of each row (ignoring any bad or object pixels) to form a one dimensional stripe profile. The stripe profile is normalised to zero median. This ensures that once the stripes are subtracted the median background level with remain the same. Each point in the normalised stripe profile is used to correct the relevant row in the input data.

2.7 Fringe Removal
Atmospheric emission lines may cause interference fringes to be present in the sky background at the level of a few percent of sky. Since the fringes can have complex spatial structures on a range of physical scales on the detector, removing them successfully is a multi-stage process. First we note that fringing is an additive effect, so if removed as part of a procedure that used night sky data as a flat field source, this would introduce a systematic error in the photometry. To perform sky fringe removal effectively requires the flat fielding to be decoupled from the defringing by, for example, using twilight sky exposures to construct the flat-field frames, where the contribution from sky emission lines is negligible. Consequently, the first stage of the process is to flat-field the dark sky science data correctly and to use a sequence of offset sky exposures to construct a fringe frame. These input frames are combined after suitable scaling to match the background levels and sigma-clipping to remove astronomical objects. The defringing process then requires solving for the fringe scale factor k in the following equation:
D( x, y ) = S ( x, y ) + kF ( x, y ) + O( x, y ) + T ( x, y

)

(2-17)

where S is the sky contribution, O is the astronomical object contribution and T is the contribution from the thermal background.


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Since the fringe pattern is characterised by more rapidly varying spatial structure than the sky and thermal contributions, the overall background variation on the target and fringe frame is temporarily removed by use of a robust low-pass filter such that:
D ( x, y ) kF ( x, y ) + O( x, y

)

(2-18)

The objects are localised, therefore a simple robust background noise estimator based on the Median of the Absolute Deviation (MAD) from the median can be used iteratively to find the scale factor k that minimises the background noise in D ( x, y ) . Allowing the scale factor to vary ensures that the relative contribution of the sky emission lines, which may vary in strength, is correctly dealt with. More complex options involving decomposing the seasonal fringe patterns into eigenfringe maps may be required at later stages in the processing but this is outside of the scope of the standard calibration pipeline. The success, scale factor background QC1 parame or otherwise, of fringe removal is monitored by the computed fringe map and also by a robust measure of the change (ratio) of the global noise/variation after fringing. This is encoded in the FRINGE_RATIO ter.

2.8 Image persistence
Astronomical images, and artefacts from preceding frames, can persist and be present on the current image. Strategies for dealing with this involve assessing the time decay characteristics and adjacency effects (i.e. image spreading) if present. In the case of no image adjacency effects, correcting for image persistence will either involve updating and maintaining a persistence mask (for combination with the confidence map), or accumulating with suitable temporal decay, a persistence map, running over a night if necessary, to subtract from the current image. For example, in the simplest case I
obs k

( x, y , t ) = I

true k

+ f вI

obs k -1

( x, y, t - t ) в e

- t /

(2-19)

where k is the image sequence number, f is the fraction of the image persisting after frame reset(s), t is the time interval between frames, and is the persistence decay constant which may be different for each detector. It is possible that image persistence may include some sort of adjacency effects. These will have to be characterised at commissioning.

2.9 Crosstalk
Images from one detector channel may produce secondary images (ghosts) on other channels either positive or negative in sign and may also even cross from one detector to another. In a stable environment, it is feasible to measure the contribution of crosstalk from one channel to another by using bright point-like sources, and thereby define a comprehensive crosstalk matrix C j ,k . Since this is environment specific, determining the final form of this matrix will be one of the commissioning tasks, although earlier laboratory-based measurements will be used to characterise its likely impact and to investigate ways of minimising the effect.


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Providing the cross-talk terms are small (i.e. <1%, the most likely scenario), then the following simple single-pass additive correction scheme will be used to correct for this problem, I j = I j -


k j

I jC

j ,k

(2-20)

where I j is the observed frame and I j the corrected version. The typical error in making a single pass correction is approximately C j ,k
2 jk

, which governs the

requirement on the magnitude of the cross-talk terms. Note also that the matrix C will in general not be symmetric.

2.10 Astrometric Calibration
From the optical design studies of VISTA we know that, to a good approximation, the astrometric distortion shows negligible variation with wavelength and is well described by a radially symmetric polynomial distortion model of the form rtrue = k1 в r + k 3 в r 3 + k 5 в r 5 + ...
(2-21)

where rtrue is an idealised angular distance from the optical axis, r is the measured distance, and k1 is the scale at the centre of the field, usually quoted in arcsec/mm. VISTA will have a central field scale, i.e. k1 value of roughly 17.09 arcsec/mm. The term due to k 5 is usually negligible and, until real sky data is available, is not worth pursuing, since other similarly sized distortions may be present. Dropping this term and rearranging the preceding equation to a more convenient form gives
rtrue = r в (1 + k3 в r 2 ) = r + k в r 3 k1
3

(2-22)

where r is the measured distance from the optical axis in arcsec using the k1 scale. If we convert all units to radians the "r-cubed" coefficient is conveniently scaled (in units of radians/radian3) and has a theoretical value of around 42 for VISTA, but will have a slight wavelength dependence. Although this type of distortion generally presents no problem for accurate calibration of individual pointings, it can lead to various complications when stacking data taken at various locations, e.g. dither sequences. This is caused by the differential non-linear distortions across individual detectors being comparable to, or larger than, the pixel size of the detector. In these cases stacking involves resampling and interpolation of some form. While these are inevitable in combining pointings to form contiguous tiled regions, they may be avoided at earlier stages, such as stacking individual detector dither sequences, by suitably limiting dither offsets and thereby both simplify and speed up the data processing. The effective scale due to the radial distortion is given by drtrue / dr = 1 + 3k в r
2

(2-23)


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which describes the local change in relative pixel scale as a function of radial distance. For example, for VISTA at 0.8 degree radius, the differential distortion term is about 2.5%. This means that a 10 arcsec shift in the centre corresponds to a 10.25 arcsec shift at the outer corners of the arrays. For the outer detectors a large fraction of this distortion occurs across individual detectors. In anticipation of this problem, we will implement a range of interpolation schemes that offer a trade off between maintaining independent pixel noise and resolution degradation. For further information see the report at
http://www.ast.cam.ac.uk/vdfs/docs/reports/astrom/.

2.11 World Coordinate System
We intend, at least initially, to characterise the WCS using the ZPN projection [RD 7] and [RD 8], i.e. ARC + polynomial distortion, using a 3rd order parameterisation (equation 2.22). The coefficients for this are encoded in the FITS header using the keywords PV2_1 and PV2_3.

2.12 Effect of Scale Change on Photometry
In addition to astrometric effects the change in scale as a function of radius also has photometric implications. The aim of conventional flat fielding is to create a flat background by normalising out perceived variations from (assumed) uniformly illuminated frames. If the sky area per pixel changes then this is reflected in a systematic error in the derived photometry. However, since it much simpler to deal with "flat" backgrounds, this problem is either usually ignored or corrected during later processing stages, together with other systematic photometry effects. The effect is simplest to envisage by considering what happens to the area of an annulus on sky when projected onto the detector focal plane. The sky annulus of 2sds becomes 2r dr on the detector, which using k to denote k 3 / k1 leads to a relative area of (1 + k в r 2 ).(1 + 3k в r 2 ) (1 + 4k в r 2 ) or in other words roughly 4 в the linear scale distortion. However, since other more unpredictable factors, such as scattered light, will also play a significant role, it is simpler procedurally to bundle all the effects together and correct all the photometric systematics in one operation. The VDFS calibration plan [AD3] describes a procedure for achieving this as an illumination correction.
(2-24)

2.13 Confidence Maps
We define a confidence map c
ij

as a normalised 1 i.e. ci , j j = 1 inverse variance

weight map denoting the "confidence" associated with the flux value in each pixel j of
1

In practice we use a 16-bit integer map such that the median level is 100%


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frame i. This has the advantage that the map is always finite and can also be used to encode for hot, bad or dead pixels, by assigning zero confidence. Furthermore, after image stacking the confidence map also encodes the effective relative exposure time for each pixel, thereby preserving all the relevant intra-pixel information for further optimal weighting. The initial confidence map for each frame is derived from regular analysis of the master calibration flat-field and dark frames and is unique for each filter/detector combination due to the normalisation. As such it also encodes individual pixel sensitivities and also allows, for example, vignetted regions to be correctly weighted when combining frames. To use the confidence maps for weighted co-addition of frames then simply requires an overall estimate of the average noise properties of the frame. This can readily be derived from the measured sky noise, in the Poisson noiselimited case, or from a combination of this and the known system characteristics (e.g. gain and readout noise). All processed frames (stacked individual detectors, tiled mosaiced regions) have an associated derived confidence map which is propagated through the processing chain in the following manner. Defining the signal si in frame i with respect to some reference signal level s s i = f i s ref , where f
i

ref

as

denotes the relative throughput (which in photometric

conditions would be exposure time), the optimum weight to use for combining the jth pixel of (suitably aligned) frames i in order to maximise the signal:to:noise of skylimited objects is defined by
x j =



i

wij x
i

ij

wij

wij = cij f i /

2 i

(2-25)

where i2 is the average noise variance in frame i, xij is the flux in pixel j on the ith frame and xj is the combined output flux. The effective exposure time is that of s The output confidence map, which is outputnoise -2 , is therefore given by j
ref

.

c j =

(



i i

cij f i / i2 ) cij f i 2 /
2 i

2

(2-26)

Special cases of this occur when f i = 1 , e.g. equal length exposures in stable photometric conditions, or the more general Poisson noise limited case, when f i / i2 = 1 , and the special variant of this when f i = 1 . These cases are given below, prior to renormalisation. c j =


i

cij /

2 i

c j =

(



i

cij )

2

i

cij f

c j =

i


i

c

ij

(2-27)


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2.14 Catalogue generation
In order to provide quality control, and astrometric and photometric calibration information, it is necessary to generate detected object (i.e. stars, galaxies) catalogues for each target frame. The catalogue generation software (e.g. [RD confidence maps for object detection and requisite information via the use of standard give here a brief description of how this will steps: · · · 12], [RD 9]) will make direct use of the parameterisation, and will produce the object descriptors. For completeness we be accomplished by use of the following

estimate the local sky background over the field and track any variations at adequate resolution to eventually remove them; detect objects/blends of objects and keep a list of pixels belonging to each blend for further analysis; parameterise the detected objects, i.e. perform astrometry, photometry and some sort of shape analysis.

2.14.1 Background analysis and object detection

The possibly-varying sky background is estimated automatically, prior to object detection, using a combination of robust iteratively-clipped estimators. Any variation in sky level over the frame will be dealt with by forming a coarsely sampled background map grid. Within each background grid pixel, typically equal to 64 в 64 image pixels, an iteratively k-sigma clipped median value of "sky" will be computed based on the histogram of flux values within the grid pixel zone. A robust estimate of sigma can be computed using the Median of the Absolute Deviation (MAD) from the median (e.g. [RD 13]). This will then be further processed to form the frame background map (e.g. [RD 9]). After removing the, possibly, varying background component, a similar robust estimate of the average sky level and sky noise per pixel can be made. This forms part of the quality control measures and also helps to robustly determine the detection threshold for object analysis. Individual objects will be detected using a standard matched filter approach (e.g. [RD 12]). Since the only images difficult to locate are those marginally above the sky noise, assuming constant noise is a good approximation (after factoring in the confidence map information) and the majority of these objects will have a shape dominated by the point spread function (PSF), which thereby defines the filter to use.
2.14.2 Image parameterisation The following image parameters can be computed efficiently and are directly used as part of the image quality control and calibration analysis.


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Isophotal Intensity - the integrated flux within the boundary defined by the threshold level; i.e. the 0th object moment I
iso

=


i

I ( xi , y i )

(2-28)

For Gaussian images, this is related to the total intensity by the factor (1 - I t / I p ) -1 , where I p is the peak flux and I t the threshold level (all relative to sky). Position - computed as an intensity-weighted centre of gravity; i.e. 1st moment x0 = y0 =


i

xi .I ( xi , y i ) / y i .I ( xi , y i ) /


i

I ( xi , y i ) I ( xi , y i )

(2-29)


i


i

Covariance Matrix - the triad of intensity-weighted 2nd moments is used to estimate the eccentricity/ellipticity, position angle and intensity-weighted size of an image



xx

= = =


i

( xi - x0 ) 2 .I ( xi , y i ) /


i

I ( xi , y i )

(2-30)

xy


i

( xi - x0 ).( y i - y 0 ).I ( xi , y i ) / ( y i - y 0 ) 2 .I ( xi , y i ) /


i

I ( xi , y i )

yy


i


i

I ( xi , y i )

The simplest way to derive the ellipse parameters from the 2nd moments is to equate them to an elliptical Gaussian function having the same 2nd moments. It is then straightforward to show (e.g. [RD 14]) that the scale size, rr , is given by
rr

=

xx

+ yy ; the eccentricity,

ecc = (
xy

xx yy

- yy ) 2 + 4.

2 xy

/ rr ; and the

position angle, is defined by, tan(2 ) = 2.

/(

- xx ) . The ellipticity, e, which

is simpler to interpret for estimating potential image distortions (e.g. trailing), is related to the eccentricity by e = 1 - (1 - ecc) /(1 + ecc) Areal Profile - a variant on the radial profile, which measures the area of an image at various intensity levels. Unlike a radial profile, which needs a prior estimate of the image centre, the areal profile provides a single pass estimate of the profile ArealProfile T + p1 , T + p 2 , T + p3 ,.....T + p logarithmically to give even sampling. The peak height, I p , is a useful related addition to the areal profile information and is defined as I p = max[ I ( xi , y i )]
i m

(2-31)

where p j ; j = 1,...m are intensity levels relative to the threshold, T, usually spaced

(2-32)

or alternatively measured by extrapolation from the areal profile if the image is saturated. The areal profile provides a direct method to estimate the seeing of objects


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in an image by enabling the average area of stellar images (point sources) at half the peak height, < A > , to be estimated. The seeing, or FWHM, is then given by FWHM = 2 < A > / . Finally a series of aperture fluxes are required for object morphological classification (see below). Aperture flux is defined as the integrated flux within some radius r of the object centre

I ap (r ) =


ir

N

I i - N в sky

(2-33)

Where boundary pixels are weighted pro-rata (soft-edged aperture photometry). A series of these is used to define the curve-of-growth, I ap (r ) -v- r, for each object.
2.14.3 Morphological Classification The object detection software will produce a series of background-corrected flux measures for each object in a set of "soft-edged" apertures of radius r/2, r/2, r, 2r, 2r ...... 32r, where r is typically fixed as the median seeing for the site+telescope+camera. The average curve-of-growth for stellar images is used to define automatically an aperture correction for each aperture used and also forms the basis for object morphological classification (required for isolating stellar images for seeing and trailing quality control).

The curve-of-growth of the flux for each object is compared with that derived from the (self-defining) locus of stellar objects, and combined with information on the ellipticity of each object, to generate the classification statistic. This statistic is designed to preserve information on the "sharpness" of the object profile and is renormalised, as a function of magnitude, to produce the equivalent of an N (0,1) measure, i.e. a normalised Gaussian of zero-mean and unit variance. Objects lying within 2-3 are generally flagged as stellar images, those below 3 (i.e. sharper) as noise-like, and those above 2-3 (i.e. more diffuse) as non-stellar. A by-product of the curve-of-growth analysis is the estimate of the average PSF aperture correction for each detector.

2.15 Photometric Zeropoint
For the purposes of quality control (e.g. sky transparency and primary photometric zeropoint will be determined for each comparison of instrumental magnitudes with the magnitudes alternative cross-check on the photometric calibration will be given a complete night of observations including regular photometric standard fields. system performance) a observation by direct of 2MASS stars. An applied retrospectively exposures in VISTA

The internal gain-correction, applied at the flat-fielding stage, should place all the detectors on a common zeropoint system (at least to first order i.e. ignoring colour equation variations between the detectors), and given a stable instrumental setup, the apparent variation of zeropoint then directly measures the change in "extinction"


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without the need to rely solely on extensive standard field coverage over a range in airmass. Therefore for any given observation of a star in a particular passband:
m
cal

=m

inst

+ ZP - ( X - 1) = m

std

+ ce

std

+

(2-34)

where ZP is the zeropoint in that passband (i.e. the magnitude at airmass unity which gives 1 count/second at the detector), m cal is the calibrated instrumental magnitude, minst is the measured instrumental magnitude (-2.5 в log10[counts/sec]), is the extinction coefficient, X is the airmass of the observation, ce std is the colour term to convert to the instrumental system, and is an error term. This assumes that the second-order extinction term and colour-dependency of are both negligible. By robustly averaging the zeropoints for all the matching stars on the frame an overall zeropoint for the observation can be obtained. Typically, the zeropoint of the instrument + telescope system should be stable throughout the night. Long-term decreases in the sensitivity of the instrument, and hence a decreasing ZP, could be caused by for example the accumulation of dust on the primary mirror. On photometric nights the extinction coefficient passband. The extinction can be monitored through the true instrumental zeropoint only varies slowly as a individual 2MASS calibrations to monitor it) or by range of airmass. should be constant in each each night either by assuming function of time (and using the making measurements over a

2.16 Illumination Correction
The two methods of determination of illumination correction differ in that the first described below requires either a rich standard star field or a series of fields with known photometry, but the second can be used before such information is available.
2.16.1 Standard Star Fields Errors in the large scale structure of the illumination of the flat fields used in signature removal can cause position dependent systematic errors in photometry. This can be a result of a varying scattered light profile between twilight (nominally when the flat field exposures would have been made) and the time when the observation was done. We can map this out by first dividing an observation of a rich photometric standard field into cells or by dividing a series of calibrator fields from, for example, 2MASS into cells. For each cell we define a median zero point of all the stars in that cell:

zp j = m

cal

-m

inst

(2-35)

(It is safe to ignore the extinction term for this exercise.) The illumination correction is then defined for each cell as:


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(2-36)

where zp is the median value of zp j over all the cells. This is defined such that a star in the jth cell is calibrated by:
m
cal

=m

inst

+ ZP - ( X - 1) - ic

j

(2-37)

2.16.2 Mesostep Analysis We assume that the spatial sensitivity of each detector can be approximated by a polynomial surface, i.e. a magnitude offset as a function of ( x, y ) measured from the centre of the detector, e.g.

ZP ( x, y ) =


hk

a hk x h y

k

(2-38)

For example, in quadratic form, at positions i and j:
ZP ( xi , y i ) = a 00 + a10 xi + a01 y i + a 20 xi2 + a11 xi y i + a 02 y
2 j 2 i 2 j

(2-39) (2-40)

ZP ( x j , y j ) = a 00 + a10 x j + a 01 y j + a 20 x + a11 x j y j + a 02 y

The difference in sensitivity/zeropoint between two positions i and j is then:
ZP ( xi , x j , y i y j ) = a10 ( xi - x j ) + (a 01 ( y i - y j ) + a 20 ( xi2 - x 2 ) j + a11 ( xi yi - x j y j ) + a02 ( yi2 - y 2 ) j

(2-41)

If we make two observations of the same star at offset positions i ( xi , y i ) and j ( x j , y j ) , we sample this function such that the difference in magnitude measured is
mij then: mij = ZP ( xi , x j , y i y j )

(2-42)

In the simplest case, observing the same star in a number of different places would allow one to measure the mij as a function of ( xi , y i ) and ( x j , y j ) . One could then fit a polynomial using least-squares and solve for the ahk . The multiple observations of multiple stars in a grid across the array ensure we can solve for the polynomial coefficients accurately.


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Functional Description

Science data from VIRCAM is processed by a single recipe, namely vircam_jitter_microstep_process. Various other recipes are provided to generate the calibration data essential for instrumental-signature removal. A variation of the science recipe, vircam_standard_process, is used on observations of standard fields (which will contain many standard stars) to produce a photometric zeropoint. The recipes will work for both the Paranal and Garching pipeline environments, but it is expected that higher-quality results will be obtained at Garching where complete nights of data will be analysed. An overview of the whole VIRCAM pipeline is illustrated in Figure 3-1.

Figure 3-1 Relationship between recipes, calibration data and data products.


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There will initially be no calibration data, and so the pipeline must be "bootstrapped" by executing the recipes in the order shown in Figure 3-2. After this, there should be the minimum set of library calibration data to run the whole pipeline in production mode.
recipe: data: static: products linearity domes, darks channel table channel table + linearity Master BPM dark darks dome flat domes dark current darks detector noise flats darks reset combine resets twilight twilights meso step persistence cross talk









Master Dark

Master dome flat Master dark current read/gain file Master reset Master twilight flat Master confidence Map

Figure 3-2 Bootstrapping table relating Calibration Observations, Recipes and Calibration Products.

3.1 Recipes
The following figures illustrate the decomposition of the processing recipes into their component functions, shown in shaded yellow circles and with the leading "vircam" stripped for clarity. Open circles show further processing carried out within the recipe and shaded mauve rectangles the QC outputs.


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Figure 3-3 vircam_reset_combine

Figure 3-4 vircam_dark_combine


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Figure 3-5 vircam_badpix_mask

Figure 3-6 vircam_dome_flat_combine


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Figure 3-7 vircam_detector_noise

Figure 3-8 vircam_linearity_analyse


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Figure 3-9 vircam_twilight_combine


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Figure 3-10 vircam_illumination_analyse


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Figure 3-11 vircam_mesotep_analyse


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Figure 3-12 vircam_persistence_analyse


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Figure 3-13 vircam_crosstalk_analyse


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Figure 3-14 vircam_sky_flat_combine


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Figure 3-15 vircam_jitter_microstep_process


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Instrument Data Description

There is only one data format, used in both IMAGING and HOWFS modes; but note, however, HOWFS data is analysed in real time on the instrument workstation and is not passed to the pipeline, and so will not be further considered here. Data frames will be in ESO modified standard FITS format [RD 5], the ESO modifications being limited to the hierarchical header proposal, and compliant with DICB standards [AD5]. The headers are also compliant with the final World Coordinate System (WCS) specification [RD 8]. Data from the full set of chips are stored in Multi Extension Format (MEF) as 32-bit signed integers [RD 6]. Offset 16-bit format is not used because data will be co-added in the data acquisition system before output. Though not a requirement, the integer format enables the use of highly efficient lossless compression.

Figure 4-1 A VIRCAM engineering readout shown displayed in the ESO-VLT Real-Time Display Tool


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Raw VIRCAM data will contain headers from ESO standard DPR, OBS, TPL dictionaries and at least the following set of data dictionaries (and see [RD 2]): · ESO-VLT-DIC.VIRCAM_CFG · ESO-VLT-DIC.VIRCAM_HOWFS · ESO-VLT-DIC.VIRCAM_ICS · ESO-VLT-DIC.VIRCAM_OS · ESO-VLT-DIC.VTCS · ESO-VLT-DIC.IRACE A full simulated FITS header is illustrated in the appendix (section 11). A full 256MByte VIRCAM exposure simulation is shown in Figure 4-1, and two examples shown organised by GASGANO in Figure 4-2 demonstrate the compliance of the data format design with ESO data-interface standards. The flow from raw data types and the templates which generate them, through the processing recipes and required calibration data, to final data products is shown in the data-processing table (Table 4-1, below).


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Figure 4-2 Synthetic VISTA data shown organised by GASGANO


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DATA FILE HOWFS reset frame HOWFS Dark Frame HOWFS dome flat HOWFS wavefront HOWFS wavefont Test observation Reset Frame Dark Frame Dark Current Persistence sky measure Persistence dark measure Dome Flat VIRCAM_ TEMPLATE howfs_cal_reset howfs_cal_dark howfs_cal_domeflat howfs_obs_exp howfs_obs_wfront img_obs_exp img_cal_reset img_cal_dark img_cal_darkcurrent DPR CATG
TECHNICAL TECHNICAL TECHNICAL ACQUISITION ACQUISITION

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DPR TYPE BIAS DARK FLAT,LAMP OBJECT, PSF-CALIBRATOR OBJECT, PSF-CALIBRATOR OBJECT BIAS DARK DARK, DARKCURRENT OBJECT, PERSISTENCE DARK, PERSISTENCE FLAT, LAMP

DPR TECH IMAGE IMAGE IMAGE IMAGE IMAGE IMAGE IMAGE IMAGE IMAGE IMAGE

RECIPE

HEADER INPUTS

CALIB DB

PRODUCTS

HOWFS data is processed on the instrument workstation

TEST CALIB CALIB CALIB CALIB

Test not processed reset_combine dark_combine dark_current Exposure parameters Exposure parameters Exposure parameters Exposure parameters WCS set Exposure parameters dome_flat_combine Exposure parameters library reset frame library dark frame

None Mean reset Mean dark Dark Current map linearity channel table library dark frame library flat field library bad-pixel map library dark frame linearity channel table Persistence constants Mean Dome Flat Dome confidence map

img_cal_persistence CALIB IMAGE

persistence_analyse

img_cal_domeflat

CALIB

IMAGE


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DATA FILE Linearity Measure Noise & Gain Twilight Flat VIRCAM_ TEMPLATE img_cal_linearity img_cal_noisgain DPR CATG CALIB CALIB

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RECIPE linearity_analyse detector_noise HEADER INPUTS Exposure parameters Exposure parameters Exposure parameters CALIB DB library dark frame channel map linearity channel table library bad-pixel map library dark frame linearity channel table library dark frame linearity channel table library flat field library confidence map persistence constants library dark frame linearity channel table library flat field library confidence map read/gain file persistence constant crosstalk matrix library fringe map photometric catalogue PRODUCTS Linearity channel table Bad pixel map Noise and gain values Mean twilight flat Sky confidence map Gain correction cross-talk matrix

DPR TYPE FLAT, LAMP, LINEARITY FLAT, LAMP, GAIN

DPR TECH IMAGE IMAGE

img_cal_twiflat

CALIB

FLAT, TWILIGHT

IMAGE

twilight_combine

Cross-Talk obs

img_cal_crosstalk

CALIB

OBJECT, CROSSTALK

IMAGE

crosstalk_analyse

Exposure parameters

Mesostep sequence

img_cal_illumination

CALIB

STD, ILLUMINATION

IMAGE

mesostep_analyse

Exposure parameters WCS set

illumination map


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DATA FILE VIRCAM_ TEMPLATE DPR CATG

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RECIPE HEADER INPUTS CALIB DB library dark frame linearity channel table library flat field library confidence map read/gain table persistence constants crosstalk matrix library fringe map photometric catalogue PRODUCTS

DPR TYPE

DPR TECH

Standard star field

img_cal_std

CALIB

STD, FLUX

IMAGE, JITTER

standard_process

Exposure parameters WCS set

photometric coefficients

Pawprint Pawprint Extd object Tile Tile extended nonstandard tile pattern nonstandard tile of extended source img_obs_tile img_obs_paw

SCIENCE SCIENCE SCIENCE SCIENCE SCIENCE img_obs_offsets SCIENCE

OBJECT OBJECT, EXTENDED OBJECT OBJECT, EXTENDED OBJECT

IMAGE, JITTER IMAGE, JITTER IMAGE, JITTER IMAGE, JITTER IMAGE, JITTER

jitter_microstep_process library dark frame linearity channel table library flat field library confidence map read/gain file persistence constants library fringe map crosstalk matrix photometric catalogue Reduced Paw Prints Associated confidence maps Object catalogues Sky map (e.g. for de-fringing, when input criteria met)

jitter_microstep_process Exposure parameters WCS set jitter_microstep_process

OBJECT, EXTENDED

IMAGE, JITTER

Table 4-1 Data Processing Table


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DRL Data Structures

5.1 Introduction to Data Products
The main pipeline products will be images stored as image extensions in multiextension FITS files, and derived parameters from the processing stored as FITS keyword/value pairs in the appropriate FITS header units. All science frames will be corrected for the standard instrumental signatures such as flat fielding and dark current, and for other possible electronic artefacts, such as crosstalk, persistence and reset anomalies. In addition all pawprint images will be astrometrically and photometrically calibrated, with the calibration information being stored as FITS header keywords in each image extension. A header keyword that associates each FITS image file with its confidence map file will also be included in the primary header unit. This keyword is in the form of a timestamp and is stored in the key ESO DRS VIR_TIME. The pipeline will also generate detected object catalogues for each science image which will be used in deriving much of the QC and calibration information. These will be stored as multi-extension FITS binary tables with a copy of the FITS header information from the FITS image files and a one-to-one correspondence of table and image extensions. Derived QC and calibration information will be added to these FITS catalogue files and also propagated to the FITS image files as described in [AD5]. In general the pipeline products fall into one of the following classes:
Science Images: images of single exposures pawprints arising from combining (stacking) jitter and microstep sequences Object Catalogues: lists of detected parameterised objects for each science image (see 5.12) Derived On-sky Calibration Information: Photometric zero points WCS coefficients other QC parameters (see Appendix for full specification) Confidence Maps: Bad pixel masks derived from dome flat sequences Single image confidence maps derived from twilight flats and bad pixel masks Stacked/interleaved image confidence maps which also include effective exposure maps Calibration Maps: Master combined dark frames Master combined flat field images Master eigen-fringe frames Other Calibration Products:


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Non-linearity coefficients for each data channel of each detector Persistence coefficients for each detector A 256x256 crosstalk matrix for the entire focal plane Illumination correction tables Products from these lists that require extra explanation are discussed in the rest of this chapter. Below is a table with the data products and their PRO.CATG and DO.CATG keyword values (where values can be used as input and output the values of these keywords are the same).
Product Master reset frame products Master reset frame Master reset frame difference image Master reset frame difference image stats table Master dark frame products Master dark frame Master dark frame difference image Master dark frame difference image stats table Master dome flat products Master dome flat frame Master dome flat frame ratio image Master dome flat frame ratio image stats table Master twilight flat products Master twilight flat frame Master twilight flat frame ratio image Master twilight flat frame ratio image stats table Master confidence map Static calibration data Channel table (initial) Photometric calibration table Linearity calculation products Channel table (revised) Bad pixel mask Detector noise products Dark current image Detector noise table Crosstalk matrix Persistence mask table Standard star products Standards table Matched standards table Illumination correction table Raw input data Reset frame Dark frame Twilight flat frame Dome flat frame Science frame PRO.CATG/DO.CATG MASTER_RESET DIFFIMG_RESET DIFFIMG_STATS_RESET MASTER_DARK DIFFIMG_DARK DIFFIMG_STATS_DARK MASTER_DOME_FLAT RATIOIMG_DOME_FLAT RATIOIMG_STATS_DOME_FLAT MASTER_TWILIGHT_FLAT RATIOIMG_TWILIGHT_FLAT RATIOIMG_STATS_TWILIGHT_FLAT MASTER_CONF CHANNEL_TABLE PHOTCAL_TAB CHANNEL_TABLE MASTER_BPM MASTER_DARK_CURRENT READGAIN_TABLE XTALK_TABLE PERSIST_MASK STANDARDS_TABLE MATCHED_STANDARDS_TABLE ILLCOR_TAB RESET_IMAGE DARK_IMAGE TWILIGHT_FLAT DOME_FLAT SCIENCE_IMAGE


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Product Final science data products Output single science images Output interleaved images Output stacked image Output interleaved and stacked image Output stacked/interleaved confidence map Output object catalogues
Table 5-1 DO and PRO categories for data products

PRO.CATG/DO.CATG SIMPLE_IMAGE INTERLEAVED_IMAGE JITTERED_IMAGE INTERLEAVED_STACKED_IMAGE CONFIDENCE_MAP OBJECT_CATALOGUE

It is imperative that a recipe continue on as best it can until all frames in the input frameset are processed. Thus in the event of some sort of failure, the recipe may have to generate `dummy' data products. These are images, tables etc. that are written to a FITS extension in the place of the data product that you would have normally expected from the given recipe. Dummy products are necessary in the event that you are processing many/all of the available extensions in one go. The dummy frames hold a position in the output data product FITS file where the real product should have gone, had there not been a failure. The types of failure that will generate dummy products are: the headers of the input frames indicate that detector was dead during the observation; an inability to load the necessary FITS image extensions for a particular detector; missing header information etc. A dummy product will be flagged with the Boolean header item ESO DRS IMADUMMY.

5.2 Channel Table
Each VIRCAM detector will be split into 16 different data channels, each with its own electronics. This means that some reduction tasks will rely on knowing the location and readout timing information for each data channel. The location and linearity information will be provided by the `channel table'. The information will be stored in a multi-extension FITS file with each extension being a FITS binary table (one for each detector). Each of the tables will contain the columns listed in below (although perhaps not in this order). The extension name should match the extension names for the input images. It is worth remembering here that there is no zeroth order coefficient, so the number of coefficient columns is the same as the polynomial order. Column Name 1 channum Type int Units Description Number of the data channel, which is an integer from 1-16. This is a unique ID for the data channel in the context of the detector of which it is a part. The X coordinate of the lower left corner of the data channel The X coordinate of the upper right corner of the data channel The Y coordinate of the lower left corner of the data channel The Y coordinate of the upper right corner of the data channel

2 3 4 5

ixmin ixmax iymin iymax

int int int int

pixels pixels pixels pixels


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6 7 8 9 10 11 12 13 14 15 . . . 14+n coeff_n dcrpix1 dcrpix2 dcd1_1 dcd1_2 dcd2_1 dcd2_2 qualfit lin_10000 norder coeff_1

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int int int int int int double double int double

pixels pixels

The X coordinate of the location within the data channel where the first pixel is read out. The Y coordinate of the location with the data channel where the first pixel is read out. Can take the values (-1,0,1). Gives the partial derivative of the fast readout axis with respect to the X axis. Can take the values (-1,0,1). Gives the partial derivative of the fast readout axis with respect to the Y axis. Can take the values (-1,0,1). Gives the partial derivative of the slow readout axis with respect to the X axis. Can take the values (-1,0,1). Gives the partial derivative of the slow readout axis to the Y axis. The quality of the linearity fit for this channel The percentage non-linearity for the current channel at a level of 10000 ADU The order of the polynomial used in the fit. The first coefficient in the fit. This must be set to 1 always

double

The nth order coefficient, where n=norder

5.3 Bad Pixel Mask
As we mentioned in section 2.13 on confidence maps, it is essential for many of the operations of the pipeline to know exactly which pixels in each image are always likely to be bad. This is done initially using a bad pixel mask. This will take the form of a FITS container file with an image extension of type byte for each detector. The values in the data array will be set to one for bad pixels and zero for good ones.

5.4 Confidence Maps
Confidence maps combine bad pixel information with variance information in composite images, as described fully in 2.13. The maps are kept as FITS MEF files in


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short integer format in which zero equates to completely bad pixel and 100 to completely good pixel.

5.5 Dark Current Image
Dark current is calculated by a looking at the time rate of change of the data in a series of dark frames taken with a variety of exposure times on a pixel by pixel basis. The result is a map with an estimate of the dark current (in ADU/sec) for each pixel.

5.6 Crosstalk Matrix
Detector crosstalk is described in section 2.9. In order to correct for this effect we need a factor that defines the effect of one channel on a second one, i.e. a crosstalk matrix. This will be generated on an occasional basis and will be stored in the form of a FITS binary table with the following columns: Column Name 1 2 3 source victim coef Type int int float Units Description The channel index of the crosstalk source The channel index of the victim of the crosstalk The scaling factor required to remove the source crosstalk from the victim.

The information in this table will be used by the crosstalk correction routine in conjunction with the channel table (5.1).

5.7 Illumination Correction Table
The effect of large scale background variation in the flat field images (usually due to scattered light) are described in section 2.16. An illumination correction table is generated by dividing the image plane into a number of boxes, using the systematic photometric zeropoint changes across the image to define the correction for each box. This is used to correct the instrumental magnitudes of subsequent observations for positional biases. This will be stored in the form of a series of binary FITS tables (one per detector) in a single MEF container with the following columns: Column Name 1 2 3 4 5 xmin xmax ymin ymax illcor Type int int int int float Units pixels pixels pixels pixels mag Description The X position of lower left corner of the box The X position of upper right corner of the box The Y position of lower left corner of the box The Y position of upper right corner of the box The illumination correction for the box


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5.8 Difference/Ratio Images
Some of the recipes will attempt to monitor performance of the detectors by comparing current images with library versions (e.g. dark frames). For additive effects like reset and dark current this can most easily be achieved with a difference image. This is simply the difference of two images in the sense of the master subtracted from the current image. Similarly for multiplicative effects like flat fielding this is most easily achieved with a ratio image which is the current image divided into the master image.

5.9 Difference/Ratio Image Statistics Tables
For recipes that monitor detector performance in particular, it is often worthwhile to keep statistical information on difference/ratio images. This is because frames are often compared to library frame either by forming a difference or a ratio and the statistics in cells or subsections across the output image can be a useful diagnostic to detector performance. A difference/ratio image statistics table will be a FITS table with the following columns defined: Column Name 1 2 3 4 5 5 6 7 8 xmin xmax ymin ymax chan mean median variance mad Type int int int int int float float float float adu adu adu adu Units pixels pixels pixels pixels Description The X position of lower left corner of the cell The X position of upper right corner of the cell The Y position of lower left corner of the cell The Y position of upper right corner of the cell The data channel to which this cell belongs. This is only useful if the whole cell fits into a data channel. The mean value in the cell The median value in the cell The variance of the values in the cell The median absolute deviation from the median of the values in the cell.

5.10 Persistence Mask Table
Dealing with image persistence properly requires knowledge of observations that were done previous to the current one. In the on-line pipeline this can be approximately accomplished by processing the observations from a particular template with respect to the times that they were done. This sort of information then can be used in conjunction with the persistence decay time constant and the end time of the current exposure to decide which frames will have affected the current image and how to scale them to correct the problem. The columns for the persistence mask table are:


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Type int

Units seconds

Description The name of the source image The end time of the source observation in seconds from 1 Jan 2000.

srcimage char

5.11 Standards Table
During the course of the pipeline reductions it will be necessary to extract information from standard astrometric and photometric catalogues. The results of this extraction will be in an Extracted Standards Table and will contain the following columns: Column Name 1 2 3 4 5­n xpredict ypredict RA Dec mags Type float float float float float Units pixels pixels degrees degrees mags Description The X position of the matching standard as predicted from the image WCS and the object's equatorial coordinates. The Y position of the matching standard as predicted from the image WCS and the object's equatorial coordinates. The standard's RA The standard's Dec Any photometric information that might exist in the standard star catalogue

5.12

Object Catalogues

The derived object catalogues are stored in multi-extension FITS files as binary tables, one for each image extension. Each detected object has an attached set of descriptors, forming the columns of the binary table, and summarising derived position, shape and intensity information (see section 2.14 for more details). The following columns are present: Column Name Description 1 Sequence number Running number for ease of reference, in strict order of image detections 2 Isophotal_flux Standard definition of summed flux within detection isophote. The x, y coordinates and errors with (1, 1) defined to be 3 X_coordinate 4 X_coordinate_err the centre of the first active pixel in the image array. See 2.14.2. 5 Y_coordinate 6 Y_coorindate_err 7 Gaussian_sigma Second moment parameters. See 2.14.2


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8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49

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Ellipticity Position_angle Areal_1_profile Areal_2_profile Areal_3_profile Areal_4_profile Areal_5_profile Areal_6_profile Areal_7_profile Areal_8_profile Peak_height Peak_height_err Aper_flux_1 Aper_flux_1_err Aper_flux_2 Aper_flux_2_err Aper_flux_3 Aper_flux_3_err Aper_flux_4 Aper_flux_4_err Aper_flux_5 Aper_flux_5_err Aper_flux_6 Aper_flux_6_err Aper_flux_7 Aper_flux_7_err Aper_flux_8 Aper_flux_8_err Aper_flux_9 Aper_flux_9_err Aper_flux_10 Aper_flux_10_err Aper_flux_11 Aper_flux_11_err Aper_flux_12 Aper_flux_12_err Aper_flux_13 Aper_flux_13_err Petr_radius Kron_radius Hall_radius Petr_flux

The number of pixels above a series of threshold levels, relative to local sky. The levels are set at T, 2T, 4T, 8T, 16T, 32T, 64T and 128T where T is the analysis threshold

Peak intensity and its error in ADU relative to local value of sky Flux and error within a specified radius aperture, typically set so that Raperture = FHWM where the quantity in angle brackets is the mean FWHM of all stellar images. This is also known as the "core radius". The apertures here correspond to (0.5, 1 2 , 1, 2 , 2, 2 2 , 4, 5, 6, 7, 8, 10, and 12) times the core radius.

Petrosian radius rp in pixels as defined in Yasuda, et al. 2001, AJ, 112, 1104. Kron radius rk in pixels as defined by Bertin and Arnouts 1996, A & A Supp, 117, 393. Hall radius rh in pixels as defined by Hall and Mackay 1984, MNRAS, 210, 979.


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50 51 52 53 54 55 56 57 58 59 60 61

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Petr_flux_err Kron_flux Kron_flux_err Hall_flux Hall_flux_err Error_bit_flag Sky_level Sky_rms Parent_or_child RA Dec Classification

Petrosian flux and error to 2rp Kron flux and error to 2rk Hall flux and error to 5rh . Alternative total flux. Bit pattern listing various processing error flags. Currently this is the number of bad pixels included in the aperture flux Local interpolated sky level from background tracker Local estimate of variation in sky level around images Flag for parent or part of de-blended deconstruct. RA and Dec of each object in degrees. These are added during WCS refinement simple flag indicating most probably classification for object: -9: Saturated -2: Object is compact (maybe stellar) -1: Object is stellar 0: Object is noise 1: Object is non-stellar an equivalent N(0,1) measure of how stellar-like an image is. It is used in deriving the classification (25) in a "necessary but not sufficient" sense. This statistic is computed from a discrete curve-of-growth analysis from the peak and aperture fluxes and also factors in ellipticity information. The stellar locus is used to define the "mean" and "sigma" as a function of magnitude such that the "statistic" can be normalised to an approximate N(0,1) distribution.

Statistic

63-80

blank

5.13 Matched Standards Table
When doing astrometric and/or photometric reduction it is necessary to match astronomical objects that appear on an image with objects from a standard catalogue. The output from such a matching algorithm is called a Matched Standards Table and will contain all the columns from both input tables (cf. 5.11 and 5.12).

5.14 Readnoise/Gain File
This is a multi-extension FITS file where each extension is a null FITS image. Each extension will have at least the following keywords in its header: Keyword chipname readnois gain Type char float float Description The name of the chip to for the current noise values The readout noise of the chip in units of electrons. The gain of the chip in units of electrons per ADU


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5.15 Photometric Calibration Table
This is a table used to define the transformation from instrumental to standard magnitudes.


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Column Name Type Description 1 filter char The name of the filter 2 extinction float The extinction coefficient for airmass of unity for the given filter. 3 offset float A pedestal value to be added to the instrumental magnitude once the colour equation has been applied. 4 columns char The standard magnitude columns from the matched standards catalogue to be used. This is the names of the columns separated by a comma. 5 coleq char The colour equation coefficients. There should be one coefficient for each of the columns mentioned in the columns field. This should be formatted as a series of floating point numbers separated by commas.


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DRL Functions

In what follows we describe the low level functions that will be driven by the VIRCAM pipeline. The parameter list describes the full API for each function. Many of the functions make use of the following structures: · vir_fits: This is a convenience structure that binds the cpl_image object for a particular image with the name of the originating FITS file, the image extension number, the primary header propertylist and the propertylist for the extension header. · vir_tfits: In a similar way, functions that get information from an existing FITS table will have parameters declared vir_tfits. This wraps a cpl_table object with the same ancillary information as above for vir_fits. · vir_mask: This is provided as a means to load and manipulate stand-alone bad pixel masks. These can come from a bad pixel mask FITS file or a confidence map. A feature of the DRL functions is an inherited status parameter. This is always the last in the parameter list and it is also the return value from each function. Each function will test the status value as its first action and return immediately if the status is bad. The error messages will be passed through the CPL error structure and hence information on the origin and cause of any error will not be lost by using inherited status. CPL currently has no facility for generating or manipulating the information required for a full World Coordinate System. As this is a vital piece of information for any astronomical observation we have sought to rectify this situation by importing a WCS package into the VIRCAM software. This package is called wcslib and was written by Mark Calabretta, who is one of the leading authorities on the representation of world coordinate systems in astronomy. The VIRCAM pipeline accesses the functions in wcslib through a simple set of wrapper routines. These were written in anticipation that CPL itself would eventually provide this kind of functionality. When it does, then just the internals of the wrapper routines will need rewriting. In this chapter we have simplified the descriptions of the functions by omitting both very obvious and repetitive features. A list of these shortcuts is included below. · We have not enumerated very obvious keywords in the input or output header lists. These include things like the data array size, data type and data dimensionality. · Inherited bad status will cause each function to return immediately without updating the CPL error message. · A fatal error condition in a function will cause an appropriate CPL error message to be set and will cause the function to return to the calling routine immediately where the pipeline can take the necessary steps to terminate gracefully. We do not include segmentation violations, arithmetic exceptions and the like in the definition of a fatal error.


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Very obvious error conditions such as corrupted input files, running out of disc space, etc have been omitted for brevity. Any function parameters that refer to image data will have the expected data type in square brackets next to the parameter name.

6.1 vircam_crosstalk
6.1.1 General Name: vircam_crosstalk Purpose: Remove electronic crosstalk from an image General Description Electrical crosstalk is removed from each data channel in the input images by means of a crosstalk matrix (see section 5.6). The latter consists of factors by which the data from one channel affects another. The applicability is to be decided during laboratory and on-sky tests. Mathematical Description: See section 2.9 for a full mathematic description of crosstalk removal. 6.1.2 Function Parameters None 6.1.3 Input Images and Required FITS Header Information. infiles (float) The input science container-file to be corrected; this must contain a full list of all the source and victim images. 6.1.4 Input Tables xtable The crosstalk matrix (see 5.6) chantab The channel table (see 5.2) 6.1.5 Output Images outfile (float) The output science image; if this is the same as the value for infile or is blank, then the output will overwrite the input. keyword type description DRS XTCOR char The name of crosstalk matrix table used 6.1.6 Output Tables None


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6.1.7 Other Output None 6.1.8 QC1 Outputs None 6.1.9 Quality Assessment Crosstalk artefacts are removed to with the expected sky noise 6.1.10 Error Conditions · There are no fatal error conditions. · There are no non-fatal error conditions

6.2 vircam_darkcor
6.2.1 General Name: vircam_darkcor Purpose: Remove reset anomaly and dark current using a library mean dark frame of matching exposure/integration time if available. General Description The data array of the input dark frame is multiplied by a predetermined factor such that it matches the scale of the reset anomaly in the target object frame. The scaled dark frame is then subtracted from the target frame. Mathematical Description: I iout = I iin - kDi where I is the input data, D is the mean dark frame data and k is the scaling factor. 6.2.2 Function Parameters vir_fits *infile [float] The input science image to be corrected. This will be overwritten by the corrected image vir_fits *darksrc [float] The input mean dark image float darkscl An input scaling factor. This corresponds to the value of k in the mathematical description above. int *status Input/output status from function. 6.2.3 Required Input FITS Header Information None


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6.2.4 Output FITS Header Information The following will be appended to the extension header for infile. keyword type description DRS DARKCOR char The name of the master dark file specified in darksrc DRS DARKSCL float The scale factor used in the subtraction 6.2.5 QC1 Outputs None 6.2.6 Quality Assessment Reset anomaly ramp removed 6.2.7 Fatal Error Conditions · Mismatched data array dimensionality between the input images · The image data fails to load 6.2.8 Non-Fatal Error Conditions None

6.3 vircam_defringe
6.3.1 General Name: vircam_defringe Purpose: Remove fringe patterns from an image using a mean fringe frame and a scaling algorithm General Description Large scale variations are removed from the input frame by dividing the image into squares over which a background median can be determined and then constructing an interpolated background correction. The fringe image is scaled by a value and subtracted from the input image. Statistics of the image show whether the scale factor used was too high or too low. The scale factor is adjusted and the fit is attempted again. This is repeated to convergence. Once convergence is achieved, then the fringes are removed with the correct scale factor. The background map variation is then added back in. Mathematical Description: I i = I i - k * Fri where I is the input image data, k is the fringe scaling factor and Fr is the fringe data. For a full description of how the scale factor and the fringe data are computed see section 2.7.


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6.3.2 Function Parameters vir_fits **infiles [float] The input science images to be corrected. These gets overwritten by the corrected images int nfiles The number of science images in the infiles list vir_fits **fringes [float] The list of fringe images int nfringes The number of fringe images in the input list vir_mask *mask The input bad pixel mask int nbsize The size of the cell for background modelling int *status Input/output status from function 6.3.3 Required Input FITS Header Information None 6.3.4 Output FITS Header Information The following will be appended to the extension header for each input image keyword type description DRS FRINGEn char The name of the fringe file used in the nth defringing pass DRS FRNGSCn float The scale factor for the nth defringing pass. 6.3.5 QC1 Outputs FRINGE_RATIO 6.3.6 Quality Assessment The FRINGE_RATIO indicates that the background variation has decreased significantly 6.3.7 Fatal Error Conditions None 6.3.8 Non-Fatal Error Conditions None


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6.4 vircam_destripe
6.4.1 General Name: vircam_destripe Purpose: Remove background stripes General Description The stripes in the background of an image are modelled by doing a block median of each row. This gives a 1d profile which is normalised to zero median. Each point on the profile is subtracted from a row in the input image. Bad pixels or object pixels can be removed with a bad pixel mask or a confidence map. Mathematical Description: None 6.4.2 Function Parameters vir_fits *in [float] The input science image to be corrected. This gets overwritten by the corrected image vir_mask *inbpm The input mask int *status Input/output status from function 6.4.3 Required Input FITS Header Information None 6.4.4 Output FITS Header Information The following will be appended to the extension header for in. keyword type description DRS STRIPECOR bool Set if the stripe correction has been done DRS STRIPERMS float The RMS of the stripe pattern removed from the image 6.4.5 QC1 Outputs None 6.4.6 Quality Assessment None 6.4.7 Fatal Error Conditions · The image data fails to load


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6.4.8 Non-Fatal Error Conditions None

6.5 vircam_flatcor
6.5.1 General Name: vircam_flatcor Purpose: Remove large and small scale gain variations by dividing science frames by a mean flat field frame. General Description The data array of the input image is divided by that from a mean flat field image. The mean flat field should have been normalised in the manner described in section 2.3. This ensures that during this reduction step we perform both for the flat field correction and the detector gain correction. Mathematical Description: I iout = I iin / Fi where I is the input data and F is the mean flat field data. 6.5.2 Function Parameters vir_fits *infile [float] The input science image to be corrected. This gets overwritten by the corrected image vir_fits *flatsrc [float] The input mean flat field image int *status Input/output status from function 6.5.3 None

Required Input FITS Header Information

6.5.4 Output FITS Header Information The following will be appended to the extension header for infile. keyword type description DRS FLATCOR char The name of the flat field image specified in flatsrc 6.5.5 QC1 Outputs None 6.5.6 Quality Assessment Robust estimates of the background of each detector image agree c.f. to expected sky noise.


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6.5.7 Fatal Error Conditions · Mismatched data array dimensionality between the input images · The image data fails to load 6.5.8 Non-Fatal Error Conditions None

6.6 vircam_genlincur
6.6.1 General Name:

vircam_genlincur Purpose: Generate linearity coefficients given a list of dome flat field exposures. General Description: A series of dark corrected exposures of a stable dome light source with a range of exposure times should be given. From the known readout, reset, dit-delay and exposure times a timing map is constructed for each pixel according to the algorithm outlined in section 2.2.2. The results are written to a new channel table. Mathematical Description: This function implements the mathematical description in section 2.2.2
6.6.2 Function Parameters vir_fits **imlist [float] The list of input dark corrected dome flat images int nimages The number of images in the list vir_tfits *chantab The input channel table for the detector represented in the input image list. This is described in section 5.2. int norder The order of the polynomial to use in the expansion; note that because the zeroth term is defined to be zero, then the number of coefficients this routine will derive is the same as the polynomial order int kconst A flag, which, if set, signals that the value of k defined in section 2.2.2 is constant for all pixels in a given image unsigned char *bpm A bad pixel mask. cpl_table *lchantab The output channel table. int *status Input/output status from function


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6.6.3 QC1 Outputs None 6.6.4 Required Input FITS Header Information The following values need to be included in the extension headers of each of the files in imlist. keyword EXPTIME ESO DET MINDIT ESO DET DITDELAY type float float float description The exposure time for the image The minimum DIT time A delay between the reset and the first read

6.6.5 Output FITS Header Information None 6.6.6 Quality Assessment The value of the qualfit and lin_10000 columns are reasonable for all channels. 6.6.7 Fatal Error Conditions · Invalid channel table. · Inability to map the data arrays of input images 6.6.8 Non-Fatal Error Conditions · Failed fit for a channel

6.7 vircam_getstds
6.7.1 General Name: vircam_getstds Purpose: Given an input FITS header, extract a list of standard stars from a catalogue that should appear on the relevant image. General Description: The header of an input image is parsed to locate and read the standard WCS FITS header keywords. The WCS is used to define the coverage of the image in equatorial coordinates. The coverage is used to select objects from the 2MASS point source catalogue. (The catalogue is expected to be made available in FITS table form.) Once the stars have been selected the information about them is written to an extracted standards table (5.11) along with their expected x,y positions based on the input WCS. Mathematical Description: N/A


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6.7.2 Function Parameters cpl_propertylist *plist The propertylist representing the FITS header of an input image. This header must have all of the keywords listed in the FITS header section below. int cache A flag, which, if set, indicates that a local cache should be set up to store catalogues that you have extracted. If used, this can significantly reduce the amount of searching that is required of the whole 2MASS catalogue and hence cut down the amount of time this routine takes. This is especially important when many exposures are being done in the same part of the sky. char *path The full path to the directory where the 2MASS FITS tables are held. cpl_table *index An index table for the catalogue FITS files ­ this parameter must be NULL on entry for the first time this routine is called and must be deleted explicitly after the last time this routine is called. cpl_table **stds The output table of standards int *status Input/output status from function 6.7.3 Required Input FITS Header Information The following must be available in the input propertylist plist. keyword CRPIX1 CRPIX2 CTYPE1 CTYPE2 CRVAL1 CRVAL2 CD1_1 CD1_2 CD2_1 CD2_2 PV2_1 PV2_3 type double double char char double double double double double double double double description All of the standard FITS WCS keywords that are relevant for the projection model to be used with VIRCAM (nominally ZPN). See [RD 8] for more specific information

6.7.4 Output FITS Header Information None 6.7.5 QC1 Outputs None


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6.7.6 Quality Assessment N/A 6.7.7 Fatal Error Conditions · Inability to read the index table. · Inability to read the catalogue tables. 6.7.8 Non-Fatal Error Conditions · No objects found in the catalogue

6.8 vircam_illum
6.8.1 General Name: vircam_illum Purpose: Work out the spatial corrections in the photometric zero point. General Description: This function takes a table of photometric standards and a table of objects extracted from a list of images. The objects in both of the input tables are matched up. The pixel space of the original image is divided up into cells of nbsize pixels on a side. The mean zero point for each cell is calculated. Next the ensemble-mean zero point is calculated for all the cells. The illumination correction is then defined for each cell as the residual zero point from that mean. The sense of the illumination correction for a cell is such that it must be subtracted from the mean frame zero point for objects in that cell. Mathematical Description: This function implements the mathematical description in section 2.16 6.8.2 Function Parameters vir_fits **images The input list of images cpl_table **mstds The list of matched standards tables (section 5.13), one for each input image cpl_propertylist **pl An array of propertylists representing the headers of the object catalogues that were derived from the input images. int nimages The number of images, matched standards catalogues and propertylists. char *filt The name of the filter for these observations. cpl_table *phottab The photometric calibration table (section 5.15) int nbsize The size of the side of a cell


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cpl_table *illcor The illumination correction table (section 5.7) float *illcor_rms The RMS of the illumination correction map int *status The input/output function status
6.8.3 Required FITS Header Information The following information is required in the extension header of the catalogues (see the parameter pl) keyword APCOR3 type description float The aperture correction for aperture 3 as calculated by vircam_imcore ESO QC SATURATION float The saturation level in counts

The following information is required from the primary header of the images
keyword type description ESO TEL AIRM START float The airmass at the start of the observation. EXPTIME float The exposure time in seconds 6.8.4 Output FITS Header Information None 6.8.5 QC1 Outputs ILLUMCOR_RMS 6.8.6 Quality Assessment Applying the correction table to the input file should result in a magnitude zero point with an RMS consistent with the mean RMS of the source photometric catalogue. This can be seen with the keyword DRS MAGZERR which is generated by vircam_photcal (6.18). 6.8.7 · · · ·

Fatal Error Conditions
Photometric calibration table is incomplete No input images No rows in matched standards catalogue Missing header information in standards catalogue or image

6.8.8 Non-Fatal Error conditions · No zeropoints can be calculated


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6.9 vircam_imcombine
6.9.1 General Name: vircam_imcombine Purpose: Combine a list of images into an output image. Allow for x,y shifting, intensity biasing, intensity scaling, image weighting and bad pixel rejection. General Description: A list of images is combined to form an output image. The output image can be either a mean of the input pixels or a median. The images can have the following done to them before combination: · the input data values for a given output pixel can be scaled by a preset amount for each input image · the input data values for a given output pixel can be biased by a preset amount for each input image · outliers can be masked and rejected Mathematical Description: None 6.9.2 Function Parameters vir_fits **fset [float] The input list of images to be combined. int nfits The number of input images int combtype A flag to determine whether the output should be a mean or a median of the input frames. 1 == median, 2 == mean int scaletype A flag to determine how the input will be scaled or biased before combining. 0: No scaling or biasing 1: Input files are biased additively to a common background median 2: Input files are scaled multiplicatively to a common background median 3: Input files are first scaled by exposure time and then biased to a common background. int xrej If set, then an extra rejection cycle will be performed. This is quite useful doing combinations in the region of bright objects. float thresh The rejection threshold in units of the background noise. cpl_image **outimage [float] The output combined image unsigned char **rejmask The output rejection mask. The value for each pixel tells how many input pixels were rejected at that position. unsigned char **rejplus


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The output positive residual rejection mask. The value for each pixel tells how many input pixels were rejected for having residuals that were positive. This is good for determining the number of cosmic ray hits there were on the input images. cpl_propertylist **drs An output propertylist for the provenance keywords to go in the DRS extension of the output file header. int *status Input/output status from function
6.9.3 Required Input FITS Header Information The following is required to be in the extension header for each image in fset. keyword type description EXPTIME float The exposure time for each input image. This is used when doing multiplicative scaling 6.9.4 Output FITS Header Information The following will appear in the extension header of outimage. keyword type description DRS PROVXXXX char A set of keywords that describes the provenance of the output file. 6.9.5 QC1 Outputs None 6.9.6 Quality Assessment N/A 6.9.7 Fatal Error Conditions · Unable to map input data arrays · Unable to create output data arrays 6.9.8 Non-Fatal Error Conditions · Input frame set is empty

6.10 vircam_imcore
6.10.1 General


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vircam_imcore Purpose: Generate a catalogue of objects on an image. General Description: This function is the main object extraction routine. It generates object catalogues for the purposes of astrometric and photometric calibration, generating catalogues of the form described in section 5.12. As a final step each object is given a stellar/non-stellar classification. Mathematical Description: This function implements the mathematical description in section 2.14
6.10.2 Function Parameters vir_fits *infile [float] The input frame from which to extract the objects vir_fits *conf [int] The input confidence map int ipix The minimum size of an object in pixels in order for that object not to be considered spurious. float thresh The detection threshold measured in units of the mean background noise int icrowd If set, then the function will attempt to de-blend merged objects float rcore The core radius in pixels for the default profile fit. int nbsize The size in pixels of the grid squares used for background estimation. int cattype The output catalogue type. This can be: 1. The 32 column INT Wide Field Camera format 2. The 80 column WFCAM format 3. A very minimal format which is just fine if only positions are required. 4. An object mask NB: option 1 corresponds to the catalogues described in section 5.12. float filtfwhm The FWHM of the smoothing kernel used in the detection algorithm cpl_table **outtab The output table of all the detected objects cpl_propertylist **extra A propertylist with QC information that one can append to a FITS header int *status Input/output status from function 6.10.3 Required FITS Header Information The following information is required from the extension header of infile.


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keyword type Description EXPTIME int The exposure time of the input data in seconds 6.10.4 Output FITS Header Information The following will be written to the extension propertylist of the input image keyword DRS SKYLEVEL DRS SKYNOISE DRS THRESHOL DRS RCORE DRS FILTFWHM type float float float float float Description The mean sky level in the image The mean sky noise in the image The threshold in ADUs for the image detection The core radius in pixels as specified in the parameter list The FWHM of the smoothing kernel in the detection algorithm float The derived seeing in pixels int If set, then this catalogue has been classified int The minimum number of pixels an object should cover int If set, then the deblending software has been run on this catalogue

DRS DRS DRS DRS

SEEING CLASSIFD MINPIX CROWDED

6.10.5 QC1 Outputs SATURATION MEAN_SKY SKY_NOISE NOISE_OBJ IMAGE_SIZE APERTURE_CORR ELLIPTICITY 6.10.6 Quality Assessment N/A 6.10.7 · · ·

Fatal Error Conditions
Negative threshold value Zero or negative sky noise estimate Unable to map input data arrays

6.10.8 Non-fatal Error Conditions · No objects found

6.11 vircam_imdither
6.11.1 General Name: vircam_imdither


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Purpose: Dither all the images in a jitter sequence into a single output image General Description: This function takes all the images and their associated confidence maps from a jitter sequence and dithers them into a single output image and confidence map. Mathematical Description: None 6.11.2 Function Parameters vir_fits **infiles [float] The input images to dither vir_fits **inconfs [int] The associated input confidence maps int ninputs The number of input images in the jitter sequence int nconfs The number of input confidence maps. If this is the same as ninputs then it is assumed that each confidence map in the input list is associated with the image located in the same place of the input image list. If this is less than ninputs then the first confidence map in the list will be used for all of the input images. cpl_propertylist *p An output property list which can be used for the extension header for the output image. This will be the extension header for the first image in the list, but with appropriate modifications to the WCS. cpl_image **out The output dithered image. cpl_image **outc The output confidence map for the dithered image int *status Input/output status from function 6.11.3 Required FITS Header Information The following information is required from the extension header of infile. keyword EXPTIME DRS XOFFDITHER DRS YOFFDITHER type int float float Description The exposure time of the input data in seconds The jitter offset in x The jitter offset in y

6.11.4 Output FITS Header Information The following will be written to the extension propertylist of the input image keyword type Description DRS PROVXXXX char A set of keywords that describes the provenance of the output file.


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6.11.5 QC1 Outputs None 6.11.6 Quality Assessment N/A 6.11.7 Fatal Error Conditions · No images to combine. · Confidence map dimensions don't match image dimensions 6.11.8 Non-fatal Error Conditions · None

6.12 vircam_interleave
6.12.1 General Name: vircam_interleave Purpose: Interleave the pixels from a microstepped sequence to form an output frame and confidence map. General Description: The fractional microstep and offsets defined by the WCS in the input file headers are used to define the size and scale of the output grid. The input data is then mapped directly onto the output grid using known offsets. The result is a frame where the input pixels have been interwoven to form a finer grid. The images can have the following done to them before combination: · the input data values for a given output pixel can be scaled by a preset amount for each input image · the input data values for a given output pixel can be biased by a preset amount for each input image No pixel rejection is possible Mathematical Description: None Quality Assessment: N/A 6.12.2 Function Parameters vir_fits **infiles The list of input microstepped observation images int ninputs The number of input files in infiles. vir_fits **inconfs


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The list of input confidence maps. If the list is NULL or has a size of zero, then no output confidence map will be created. If the list has a size that is less than the size of the input file list (infiles), then only the first one will be used (i.e. each input image has the same confidence map). If the list has the same number of maps as the input images, then all the listed confidence maps will be used to form the output confidence map. int nconfs The number of confidence maps in inconfs. int nsteps The number of steps in the microstep pattern, e.g. for a 3x3 microstep pattern, this should be set to 3. cpl_propertylist **p A propertylist that will be used for the output image. This will be the header for the first image in the input image frameset (infiles), with the appropriate modifications to the WCS. cpl_image **outimage The output interleaved image cpl_image **outconf The output confidence map (if any) int *status Input/output status from function
6.12.3 Required Input FITS Header Information The following information is required from the extension header of the first file in the infiles list. keyword CRPIX1 CRPIX2 CTYPE1 CTYPE2 CRVAL1 CRVAL2 CD1_1 CD1_2 CD2_1 CD2_2 PV2_1 PV2_3 type double double char char double double double double double double double double description All of the standard FITS WCS keywords that are relevant for the projection model to be used with VIRCAM (nominally ZPN). See [RD 8] for more specific information.

The following information is required from the extension header from each of the files in the infiles list.
keyword type description DRS XOFFMICRO float The X offset in pixels of the current image relative to the first image in the microstep sequence. DRS YOFFMICRO float The Y offset in pixels of the current image relative to the


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first image in the microstep sequence. float The median value of the background

6.12.4 Output FITS Header Information WCS keywords as above modified for the new sampling. These are written to the output propertylist p. The following will also appear in p. keyword type description DRS PROVXXXX char A set of keywords that describes the provenance of the output file. 6.12.5 QC1 Outputs None 6.12.6 Quality Assessment N/A 6.12.7 Fatal Error Conditions · Failure to access input data · Input frame list has no entries 6.12.8 Non-Fatal Error Conditions None

6.13 vircam_lincor
6.13.1 General Name: vircam_lincor Purpose: Use linearity coefficients and timing information to put input data onto a linear scale. General Description The linearity coefficients for each data channel are combined with readout timing information in the manner described in section 2.2.1 to create a linearised data array for the input file. Mathematical Description: This function implements the mathematical description given in section 2.2.1. See that section for a full description. 6.13.2 Function Parameters vir_fits *infile The input image to be linearised


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vir_tfits *lchantab The channel table which is appropriate for this image. int kconst If set, then the value of k in section 2.2 is constant for all pixels in the image. int *status Input/output status from function
6.13.3 Required Input FITS Header Information The following items are required from the extension header of infile. keyword EXPTIME ESO DET MINDIT ESO DET DITDELAY type float float float description The exposure time for the image The minimum DIT time A delay between the reset and the first read

6.13.4 Output FITS Header Information The following items will appear in the extension header of infile: keyword type description DRS LINCOR char The name of the FITS file of the channel table used to linearise the data 6.13.5 QC1 Outputs None 6.13.6 Quality Assessment N/A 6.13.7 Fatal Error Conditions · Inability to map input data. · Channel table has incorrect information 6.13.8 Non-Fatal Error Conditions None

6.14 vircam_matchstds
6.14.1 General Name: vircam_matchstds Purpose: Match a list of standard stars (from vircam_getstds) to the (x,y) positions of objects on an image.


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General Description: This routine matches the objects found on an image with a list of objects that have been extracted from a standard catalogue. The (x,y) coordinates in both lists are compared and Cartesian offsets are found which cause the maximum number of objects to match. Output will be to a matched standards table (5.13). Mathematical Description: N/A 6.14.2 Function Parameters cpl_table *objtab The input table with the programme objects. Must have columns called X_coordinate and Y_coordinate (as one gets from vircam_imcore). cpl_table *stdstab The input table with the template objects. Must have columns called xpredict and ypredict (as one gets from vircam_getstds) float srad A search radius in pixels. This helps to define the number of points used in the grid search cpl_table **outtab The output table with both sets of Cartesian coordinates plus any extra information that appears in stdstab. int *status Input/output status from function 6.14.3 Required FITS Header Information None 6.14.4 Output FITS Header Information None 6.14.5 QC1 Outputs None. 6.14.6 Quality Assessment N/A 6.14.7 Fatal Error Conditions · Input tables do not have the required columns 6.14.8 Non-Fatal Error Conditions · One of the input catalogues has no objects


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6.15 vircam_matchxy
6.15.1 General Name: vircam_matchxy Purpose: Work out relative jitter offsets by cross-correlating the locations of objects on a set of frames. General Description: Two catalogues of objects derived from two images (a programme image and a template image) are given. A search algorithm is used to try and maximise the number of objects that match between the two lists, by varying the Cartesian offsets. No axis flipping or rotation is allowed. The output is the x,y offsets. These can be applied to a whole group of files by the calling routine in order to define the relative offsets for a complete jitter sequence. The offsets are defined in the sense: X = X template - X programme

In order to minimise the effect of the astrometric distortion on the offset solution, it is generally advisable that the input coordinates of the programme table should be biased by offsets that have been calculated from the initial WCS in the input images. Mathematical Description: None
6.15.2 Function Parameters cpl_table *progtab The table of objects appearing on the `programme' frame. Must have columns X_coordinate and Y_coordinate. cpl_table *temptab The table of objects appearing on the `template' frame. Must have columns X_coordinate and Y_coordinate. float srad The search radius in pixels. This is used to define the number of points for the grid search. float *xoffset The returned value of the x Cartesian offset float *yoffset The returned value of the y Cartesian offset int *nm The number of objects that matched between the two input lists int *status Input/output status from function 6.15.3 Required FITS Header Information None


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6.15.4 Output FITS Header Information None 6.15.5 QC1 Outputs None 6.15.6 Quality Assessment N/A 6.15.7 Fatal Error Conditions · The input tables do not have the required columns. 6.15.8 Non-Fatal Error Conditions · One of the tables has no objects.

6.16 vircam_mkconf
6.16.1 General Name: vircam_mkconf Purpose: Make an initial confidence map from two flat field images General Description: A mean flat field image and a bad pixel mask are given. The good pixels are given a confidence value as described below and the bad ones are assigned a value of zero. Mathematical Description: `Good' pixels will be given a confidence of: Ci = 100 Fi / F

where Fi is the pixel's value in the input flat field map, and F is the mean value in the flat field map. A maximum confidence of 110 is allowed. Quality Assessment: N/A
6.16.2 Function Parameters cpl_image *flat The input flat field image char *flatfile The file from which flat originated vir_mask *bpm The input bad pixel mask image cpl_image **outconf The output confidence map image cpl_propertylist **drs


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A propertylist to be used to store the output DRS keywords int *status The input/output function status
6.16.3 Required FITS Header Information None 6.16.4 Output FITS Header Information keyword type description DRS FLATIN char The name of the FITS file from which the flat data originated. DRS BPMIN char The name of the FITS file from which the bad pixel map data originated 6.16.5 QC1 Outputs None 6.16.6 Quality Assessment N/A 6.16.7 Fatal Error Conditions · One or other of the input images is unreadable. 6.16.8 Non-Fatal Error Conditions None

6.17 vircam_persist
6.17.1 General Name: vircam_persist Purpose: Remove effects of image persistence General Description: Images can persist on an IR detector after it has been read and reset. This persistence can be characterised by an exponential decay time. To correct this, a list of all the images that have been taken before the current image should be passed into this routine, along with their respective observational end times (in seconds from some zero point). This is the persistence mask defined in section 5.10. Using this information, an appropriate decay model and the ending time of the current exposure, a persistence map is built up. This map is then subtracted from the input image. Mathematical Description:


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This function implements the mathematical description in section 2.8.
6.17.2 Function Parameters float decay The decay constant in seconds as described in section 2.8. float fract The fraction of the ambient intensity that persists right after reset (i.e. no decay time). 6.17.3 Input Images and Required FITS Header Information infile (float) The input science image to be corrected. keyword type description EXPTIME int The exposure time of the input data DATE-OBS char The UTC date of the start of the exposure 6.17.4 Input Tables ptable The persistence mask. See section 5.10. 6.17.5 Output Images outfile (float) The output science image; if this is the same as the value for infile or is blank, then the output will overwrite the input. keyword type description DRS PERMASK char The name of the persistence mask used 6.17.6 Output Tables None 6.17.7 Other Output None. 6.17.8 QC1 Outputs None 6.17.9 Quality Assessment Persistent images removed to within the mean sky noise. 6.17.10 Error Conditions · The following conditions will cause fatal errors o Negative or zero exposure time. o Mismatched dimensionality of data arrays.


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There are no non-fatal error conditions

6.18 vircam_photcal
6.18.1 General Name: vircam_photcal Purpose: Work out the photometric zero point for stars in an image General Description: The instrumental and standard magnitudes of objects on a frame are compared and a photometric zero point is calculated. Mathematical Description: This function implements the mathematical description in section 2.15 6.18.2 Function Parameters vir_fits **images The input list of images cpl_table **mstds The list of matched standards tables (section 5.13), one for each input image cpl_propertylist **pl An array of propertylists representing the headers of the object catalogues that were derived from the input images. int nimages The number of images, matched standards catalogues and propertylists. char *filt The name of the filter for these observations. cpl_table *photcal The photometric calibration table (section 5.15) int *status The input/output function status 6.18.3 Required FITS Header Information The following information is required in the extension header of the catalogues (see the parameter pl) keyword EXPTIME APCOR3 type description float The exposure time in seconds float The aperture correction for aperture 3 as calculated by vircam_imcore APCOR5 float The aperture correction for aperture 5 as calculated by vircam_imcore ESO QC SATURATION float The saturation level in counts ESO DRS RCORE float The core radius used in the object detection

The following information is required from the primary header of the images


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keyword type description ESO TEL AIRM START float The airmass at the start of the observation. 6.18.4 Output FITS Header Information This routine calculates a zeropoint for two different apertures. It calculates these for each individual image and calculates a collective zeropoint for all the images in the list. In the table below the suffix "im" refers to results on an image by image basis and `all' refers to the collective solution. keyword DRS ZPIM3 type description float The calculated photometric zero point for the image in aperture 3 ZPSIGIM3 float The RMS of the photometric zero point for the image in aperture 3 ZPIM5 float The calculated photometric zero point for the image in aperture 5 ZPSIGIM5 float The RMS of the photometric zero point for the image in aperture 5 LIMIT_MAG3 float The 5 sigma limiting magnitude for this image in aperture 3 LIMIT_MAG5 float The 5 sigma limiting magnitude for this image in aperture 5 MAGNZPTIM int The number of stars used in the zero point calculation in this image ZPALL3 float The calculated photometric zero point for all images in aperture 3 ZPSIGALL3 float The RMS of the photometric zero point for all images in aperture 3 ZPALL5 float The calculated photometric zero point for all images in aperture 5 ZPSIGALL5 float The RMS of the photometric zero point for all images in aperture 5 MAGNZPTALL int The number of stars used in the zero point calculation in all images

DRS DRS DRS DRS DRS DRS DRS DRS DRS DRS DRS

6.18.5 QC1 Outputs MAGZPT MAGZERR MAGNZPT LIMITING_MAG


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6.18.6 Quality Assessment The RMS of the zeropoint is with the expected limits of the 2MASS catalogue, notwithstanding the quality of the observing conditions. 6.18.7 · · · ·

Fatal Error Conditions
Photometric calibration table is incomplete No input images No rows in matched standards catalogue Missing header information in standards catalogue or image

6.18.8 Non-Fatal Error conditions None

6.19 vircam_platesol
6.19.1 General Name: vircam_platesol Purpose: Work out a plate solution for an image given the RA, Dec, x, y values for objects on that image. General Description: Cartesian and equatorial coordinates are fitted to standard plate solution models of either 4 or 6 constants (4-constant model being more robust but at the cost of assuming zero shear and no scale difference. The default therefore is 6). If so desired, the difference in the predicted x,y coordinates and the true x,y coordinates can be used to adjust the tangent point first to block correct for telescope pointing error. The median difference of the equatorial coordinates between that implied from the two sets of Cartesian coordinates is used to update the tangent point. A full least-squares solution is performed and the results are written back to the given FITS WCS header structure. Mathematical Description: For a 6 constant model, fits are done with the input standards for the equations:

= ax + by + c = dx + ey + f

(6-1) (6-2)

to find values of a, b, c, e, d and f. For a 4-constant model the same equations are used, but with the constraint that a = e and b = d. See section 2.10 for information on how the expected projection geometry will be incorporated.
6.19.2 Function Parameters cpl_propertylist *plist


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The propertylist which represents the FITS header for an input image. It must have a rough FITS WCS already if the tangent point is going to be repositioned. cpl_table *matchedstds A matched standards table containing at least the following columns: X_coordinate, Y_coordinate, xpredict, ypredict, ra, dec. int nconst The number of plate constants to be used. This can be either 6 (default) or 4. int shiftan If set, then the difference between the predicted and the true cartesian coordinates of the objects in the matched standards catalogue will be used to redefine the equatorial coordinates of the reference point of the WCS. int *status The input/output function status.
6.19.3 Required FITS Header Information keyword CRPIX1 CRPIX2 CTYPE1 CTYPE2 CRVAL1 CRVAL2 CD1_1 CD1_2 CD2_1 CD2_2 PV2_i, i=1~5 NAXIS1 type double double char char double double double double double double double description All of the standard FITS WCS keywords that are relevant for the projection model to be used with VIRCAM (nominally ZPN). See [RD 8] for more specific information. NB: These will all be modified by this function on output.

int int

NAXIS2

The X size of the data array from which the catalogue was generated The Y size of the data array from which the catalogue was generated

6.19.4 Output FITS Header Information As above, but modified by the fit done in this routine, also: keyword DRS STDCRMS DRS NUMBRMS DRS WCSRAOFF type float int float description The RMS of the WCS fit. The number of stars used in the WCS fit The equatorial coordinates of the central pixel of the image is calculated both before and after the plate solution is found. This is the difference in the RA (in arcseconds)


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DRS WCSDECOFF float The equatorial coordinates of the central pixel of the image is calculated both before and after the plate solution is found. This is the difference in the DEC (in arcseconds)
6.19.5 QC1 Outputs WCS_DCRVAL1 WCS_DCRVAL2 WCS_DTHETA WCS_SCALE WCS_SHEAR (6-constant model) WCS_RMS 6.19.6 Quality Assessment DRS STDCRMS is within the expected internal consistency of the input astrometric data convolved with a centring error. 6.19.7 · · ·

Fatal Error Conditions
Unsupported value of nconst. Too few standards for the fit. Required columns don't exist in input matched standards table.

6.19.8 Non-Fatal Error conditions None


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Data Reduction CPL Plugins

Each recipe has a direct correspondence to a CPL plugin; but the correspondence between raw data-types and recipes is not one-to-one because, in some cases, science data are used to produce calibration frames. Each plugin is documented below. Where a calibration product is created by the recipe, the value in parenthesis after the file specifies the value of the PRO CATG keyword in the output file header. The parenthesis after the input data specifications indicate whether the data are required or optional and the DO CATG keyword that must appear in the sof file. The plugins may receive error messages from the functions that they call. If these are considered by the function to be fatal, then the plugin will exit gracefully. If the errors are considered to be just a warning the plugin may choose to proceed with caution, to get the information it needs from another source or fail gracefully. As in the previous section we do not include conditions such as segmentation violations and arithmetic exceptions in the list of fatal errors. Only error conditions that occur within the plugin, and outside of the VIRCAM functions documented in section 6, will be documented here. In addition, all error conditions which would lead to the writing of a dummy product will be documented here. All recipes will fail if they are unable to identify RAW and CALIB frames or if they cannot make sense of the DO CATG values specified in the sof file. All of the parameters that can be changed on the command line are listed for each recipe. It is worth noting that esorex allows the user to change parameters in a semipermanent way using environment variables. Full details on the names of these environment variables can be found by using the ­man-page switch with esorex. Finally all recipes have a parameter that is in addition to the ones documented below. This is ext and it defines the FITS extension number for the input files that are to be processed by the recipe. This allows the recipe to either process a single extension or all extensions (ext = 0).

7.1 vircam_reset_combine
Name:

vircam_reset_combine Purpose: Combine a sequence of reset frames to form a mean frame. Compare to a library reset frame to provide information on the stability of the pedestal and reset structure Type: Detector calibration Input Data: · List of reset frames (required, RESET_IMAGE) · Library mean reset frame (optional, MASTER_RESET) · Channel table (optional, CHANNEL_TABLE) · Library bad pixel map (optional, MASTER_BPM) or library confidence map (optional, MASTER_CONF)


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Parameters: int combtype Determines the type of combination that is done to form the output map. Can take the following values 1. The output pixels are medians of the input pixels 2. The output pixels are means of the input pixels int scaletype Determines how the input data are scaled or offset before they are combined. Can take the following values: 0. No scaling or biasing 1. All input frames are biased additively to bring their backgrounds to a common median level. 2. All input frames are biased multiplicatively to bring their backgrounds to a common median level. 3. All input frames are scaled to a uniform exposure time and then additively corrected to bring their backgrounds to a common median level. int xrej If set, then an extra rejection cycle will be run. int thresh The rejection threshold in numbers of background sigmas. int ncells If a difference image statistics table is being done, then this is the number of cells in which to divide each readout channel. The value must be a power of 2, up to 64 Algorithm: · Combine the sequence of reset frames into a single mean with rejection. · Calculate RMS of mean reset frame. · If a library master reset frame is given, then subtract it from the mean frame created here to form a difference image. Calculate a mean and RMS of the difference image. · If a channel map is included, then this is used to split each data channel of the difference image into cells and do a robust median and RMS estimate in each. The results of this analysis are written to a difference image statistics table. · If a master bad pixel mask or a master confidence map is included these are used to mask out bad pixels in the above statistical analyses. Outputs: · New master reset frame (MASTER_RESET) · Difference image (DIFFIMG_RESET) · Reset difference image statistics table (DIFFIMG_STATS_RESET) QC1 Parameters: RESETMED RESETRMS RESETDIFF_MED RESETDIFF_RMS VIRCAM Functions Used:


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vircam_imcombine Fatal Error Conditions: · Null input frameset · Input frameset headers incorrect meaning that RAW and CALIB frames cannot be distinguished · No reset frames in the input frameset · Inability to save output products Non-fatal Error Conditions: · Missing calibDB reset frame (No comparison with master frame done and no output difference image) · Missing or invalid channel table (No difference image statistics table made) · Missing bad pixel map or missing confidence map (No bad pixel rejection during statistical analysis) Conditions Leading To Dummy Products: · Reset frame image extensions won't load · The detector for the current image extension has been disabled · Failure in combination routine · Master reset frame image extension won't load or is a dummy · Channel table FITS extension won't load, is invalid or is a dummy

7.2 vircam_dark_combine
Name:

vircam_dark_combine Purpose: Combine a series of dark frames taken with a particular integration and exposure time combination. Compare with a similarly observed master dark frame. Calculate variation in the reset anomaly structure and scale. Type: Detector calibration Input Data: · List of dark frames (required, DARK_IMAGE) · Library mean dark frame (optional, MASTER_DARK) · Library bad pixel mask (optional, MASTER_BPM) or library confidence map (optional, MASTER_CONF) · Channel table (optional, CHANNEL_TABLE) Parameters: int combtype Determines the type of combination that is done to form the output map. Can take the following values 1. The output pixels are medians of the input pixels 2. The output pixels are means of the input pixels int scaletype


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Determines how the input data are scaled or offset before they are combined. Can take the following values: 0. No scaling or biasing 1. All input frames are biased additively to bring their backgrounds to a common median level. 2. All input frames are biased multiplicatively to bring their backgrounds to a common median level. 3. All input frames are scaled to a uniform exposure time and then additively corrected to bring their backgrounds to a common median level. int xrej If set, then an extra rejection cycle will be run. int thresh The rejection threshold in numbers of background sigmas. int ncells If a difference image statistics table is being done, then this is the number of cells in which to divide each readout channel. The value must be a power of 2, up to 64 Algorithm: · Combine the sequence of dark frames with rejection. · In conjunction with bad pixel map or confidence map, assess the number of rejected pixels with positive residuals to give an indication of the rate of cosmic ray hits and their properties. · Work out a robust median in a region that is unaffected by reset anomaly. · If a library master dark frame is given, then subtract it from the mean frame created here to form a difference image. Calculate a mean and RMS of the difference image. · If a channel map is included, then this is used to split each data channel of the difference image into cells and do a robust median and RMS estimate in each. The results of this analysis are written to a difference image statistics table. · If a master bad pixel mask or a master confidence map is included these are used to mask out bad pixels in the above statistical analyses Outputs: · New mean dark frame (MASTER_DARK) · Dark frame difference image (DIFFIMG_DARK) · Dark difference image statistics table (DIFFIMG_STATS_DARK) QC1 Parameters: DARKMED DARKRMS DARKDIFF_MED DARKDIFF_RMS PARTICLE_RATE STRIPERMS VIRCAM Functions Used: vircam_imcombine, vircam_destripe Fatal Error Conditions:


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Null input frameset Input frameset headers incorrect meaning that RAW and CALIB frames cannot be distinguished · No dark frames in the input frameset · Inability to save output products Non-fatal Error Conditions: · Missing calibDB dark frame (No comparison with master frame done and no output difference image) · Missing or invalid channel table (No difference image statistics table made) · Missing bad pixel map or missing confidence map (No bad pixel rejection during statistical analysis) Conditions Leading To Dummy Products: · Dark frame image extensions won't load · The detector for the current image extension has been disabled · Failure in combination routine · Master dark frame image extension won't load or is a dummy · Channel table FITS extension won't load, is invalid or is a dummy

7.3 vircam_dark_current
Name:

vircam_darkcurrent Purpose: Calculate the dark current of a detector using a series of dark exposures with varying exposure times. Type: Detector Calibration Input Data: · A series of dark exposures at a variety of different exposure times (required, DARK_IMAGE) · Library bad pixel mask (optional, MASTER_BPM) or library confidence map (optional, MASTER_CONF) Parameters: float thresh The threshold in units of background sigma above or below the local mean value. This defines whether a data point in the fit is bad or not. Algorithm: · Perform robust iterative linear fit across all exposures at each pixel position · At each pixel position, the slope of the fit represents the dark current expressed in units of ADUs per second. · Where the bad pixel mask is set the output value is set to zero. Outputs: · Dark current map (MASTER_DARK_CURRENT)


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QC1 Parameters: DARKCURRENT VIRCAM Functions Used: None Fatal Error Conditions: · Null input frameset · Input frameset headers incorrect meaning that RAW and CALIB frames cannot be distinguished · Not enough dark frames in the input frameset · Missing exposure times in input headers · Inability to save output products Non-fatal Error Conditions: · Missing bad pixel map or missing confidence map (No bad pixel rejection during statistical analysis) Conditions Leading To Dummy Products: · Dark frame image extensions won't load · The detector for the current image extension has been disabled

7.4 vircam_dome_flat_combine
Name:

vircam_dome_flat_combine Purpose: Combine a series of dome flat images to create a mean dome flat. Compare with a similarly observed master dome flat frame. Type: Detector calibration Input Data: · List of dome flat exposures all taken with the same exposure parameters (required, DOME_FLAT) · Master dark frame of the same exposure parameters as above (required, MASTER_DARK) · Master mean dome flat (optional, MASTER_DOME_FLAT) · Channel map (optional, CHANNEL_TABLE) · Master bad pixel mask (optional, MASTER_BPM) or master confidence map (optional, MASTER_CONF) Parameters: float lthr Any input flat with a mean value of less than this will be excluded as being underexposed. float hthr Any input flat with a mean value of more than this will be excluded as being overexposed. int combtype Determines the type of combination that is done to form the output map. Can take the following values 1. The output pixels are medians of the input pixels


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2. The output pixels are means of the input pixels int scaletype Determines how the input data are scaled or offset before they are combined. Can take the following values: 0. No scaling or biasing 1. All input frames are biased additively to bring their backgrounds to a common median level. 2. All input frames are biased multiplicatively to bring their backgrounds to a common median level. 3. All input frames are scaled to a uniform exposure time and then additively corrected to bring their backgrounds to a common median level. int xrej If set, then an extra rejection cycle will be run. int thresh The rejection threshold in numbers of background sigmas. int ncells If a ratio image statistics table is being done, then this is the number of cells in which to divide each readout channel. The value must be a power of 2, up to 64 Algorithm: · Remove any images that are saturated or underexposed. · Process remaining images to linearise and remove dark current. · Combine the dome flat exposures with rejection. · If a library master dome flat frame is given, then divide the mean frame created here into the master to form a ratio image. Calculate a mean and RMS of the ratio image. · If a channel map is included, then this us used to split each data channel of the ratio image into cells and do a robust median and RMS estimate in each. The results of this analysis are written to a ratio image statistics table. · If a master bad pixel mask or a master confidence map is included these are used to mask out bad pixels in the above statistical analyses Outputs: · New master dome flat (MASTER_DOME_FLAT) · Ratio image (RATIOIMG_DOME_FLAT) · Ratio image statistics table (RATIOIMG_DOME_FLAT_STATS) QC1 Parameters: FLATRMS FLATRATIO_MED FLATRATIO_RMS VIRCAM Functions Used: vircam_imcombine, vircam_darkcor, vircam_lincor Fatal Error Conditions: · Null input frameset · Input frameset headers incorrect meaning that RAW and CALIB frames cannot be distinguished


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No dome flat frames in the input frameset No master dark frame in input frameset Inability to save output products Error Conditions: Missing calibDB dome frame (No comparison with master frame done and no output ratio image) · Missing or invalid channel table (No ratio image statistics table made) · Missing bad pixel map or missing confidence map (No bad pixel rejection during statistical analysis and no linearisation done) Conditions Leading To Dummy Products: · Dome frame image extensions won't load · The detector for the current image extension has been disabled · All the dark corrected images are either below the under-exposure threshold or above the over-exposure threshold. · Master dark frame image extension won't load or is a dummy · Failure in combination routine · Channel table FITS extension won't load, is invalid or is a dummy

7.5 vircam_detector_noise
Name:

vircam_detector_noise Purpose: Measure the detector readout noise and gain Type: Detector calibration Input Data · Two dome flat frames taken with the same exposure parameters (required, DOME_FLAT) · Two dark frames taken with the same exposure parameters as the dome flats (required, DARK_IMAGE) · A master bad pixel mask (optional, MASTER_BPM) or master confidence map (MASTER_CONF) Parameters: float thresh The threshold in units of background sigma above or below the local mean value. This is used during the statistical analyses of the input images and difference images. Algorithm: · Form difference images of the two dome flats and the two dark frames · Do statistics as outlined in section 2.4 to give an estimate of read noise and gain Outputs: · Read noise and gain estimates for each extension. These are written to a paf file.


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Read noise and gain estimates for each extension written to a detector noise table (READGAIN_TABLE) QC1 Parameters: READNOISE GAIN VIRCAM Functions Used: None Fatal Error Conditions: · Null input frameset · Input frameset headers incorrect meaning that RAW and CALIB frames cannot be distinguished · Insufficient dark or flat exposures · Inability to save output products Non-fatal Error Conditions: · Missing bad pixel map or missing confidence map (No bad pixel rejection during statistical analysis and no linearisation done) No stats are calculated. Conditions Leading To Dummy Products: · The image extensions won't load · Unphysical statistical result · The detector for the current image extension is flagged dead.

7.6 vircam_linearity_analyse
Name:

vircam_linearity_analyse Purpose: Create detector channel linearity curves and bad-pixel maps Type: Detector calibration Input Data: · A series of dome flat exposures taken under constant illumination with varying integration times (required, DOME_FLAT). · Channel map (required, CHANNEL_TABLE) · A list of raw dark frames containing a series of dark exposures with the same exposure parameters for each of the input dome flat exposures (required, DARK_IMAGE) Parameters: int nord The order of the polynomial to be fit to the linearity curve of each channel float lthr The lower threshold in the ratio maps to define a pixel as bad. Units are in background sigma of the ratio map. float hthr


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The upper threshold in the ratio maps to define a pixel as bad. Units are in background sigma of the ratio map float overexp The maximum number of ADUs a dome flat image may have on average before it is considered to be over-exposed. Algorithm: · Combine all sets of raw dark images into mean dark images · Process each flat exposure by removing the reset anomaly with the appropriate dark frame · Combine the dome series with rejection into a normalised mean flat field · Divide the series by the mean frame · Find pixels in the ratio maps whose values are over or under the input threshold value and flag them as bad · Compute the number of bad pixels in this new bad pixel mask. · Combine timing information from channel map and known read and reset times to derive the k factors needed as indicated in section 2.2.2. · Solve for coefficients and store them in a new channel table. Outputs: · Output channel table with new linearity information (CHANTAB) · Output bad pixel mask (MASTER_BPM) QC1 Parameters: LINEARITY LINFITQUAL BAD_PIXEL_STAT VIRCAM Functions Used: vircam_darkcor, vircam_genlincur Fatal Error Conditions: · Null input frameset · Input frameset headers incorrect meaning that RAW and CALIB frames cannot be distinguished · No dark or dome flat frames in input frameset · No channel table in input frameset · Inability to save output products Non-fatal Error Conditions: · Not enough dome flats in the series for the requested order of fit. Order is adjusted downwards. Conditions Leading To Dummy Products: · The dark/dome image extensions won't load · Channel table fits extension won't load, won't verify or is flagged as a dummy. · The detector for the current image extension is flagged dead. · vircam_genlincur failed

7.7 vircam_twilight_flat_combine
Name:


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vircam_twilight_flat_combine Purpose: Combine a series of twilight flat images to create a mean twilight flat and initial confidence map. Compare with a similarly observed master twilight flat frame. Type: Detector calibration Input Data: · List of twilight flat exposures all taken with the same exposure parameters (required, TWILIGHT_FLAT) · Master dark frame of the same exposure parameters as above (required, MASTER_DARK) · Master mean twilight flat (optional, MASTER_TWILIGHT_FLAT) · Channel map (optional, CHANNEL_TABLE) · Master bad pixel mask (optional, MASTER_BPM) or master confidence map (optional, MASTER_CONF) Parameters: float lthr Any input flat with a mean value of less than this will be excluded as being underexposed. float hthr Any input flat with a mean value of more than this will be excluded as being overexposed. int combtype Determines the type of combination that is done to form the output map. Can take the following values 1. The output pixels are medians of the input pixels 2. The output pixels are means of the input pixels int scaletype Determines how the input data are scaled or offset before they are combined. Can take the following values: 0. No scaling or biasing 1. All input frames are biased additively to bring their backgrounds to a common median level. 2. All input frames are biased multiplicatively to bring their backgrounds to a common median level. 3. All input frames are scaled to a uniform exposure time and then additively corrected to bring their backgrounds to a common median level. int xrej If set, then an extra rejection cycle will be run. int thresh The rejection threshold in numbers of background sigmas. int ncells If a ratio image statistics table is being done, then this is the number of cells in which to divide each readout channel. The value must be a power of 2, up to 64


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Algorithm: · Remove any images that are saturated or underexposed. · Process remaining images to linearise and remove dark current. · Combine the twilight flat exposures with rejection. Normalise by its median. · If a library master twilight flat frame is given, then divide the mean frame created here into the master to form a ratio image. Calculate a mean and RMS of the ratio image. · If a channel map is included, then this us used to split each data channel of the ratio image into cells and do a robust median and RMS estimate in each. The results of this analysis are written to a ratio image statistics table. · If a master bad pixel mask or a master confidence map is included these are used to mask out bad pixels in the above statistical analyses · Use the mean flat and bad pixel map to create an initial confidence map. Outputs: · New master twilight flat (MASTER_TWILIGHT _FLAT) · Ratio image (RATIOIMG_TWILIGHT _FLAT) · Ratio image statistics table (RATIOIMG_TWILIGHT _FLAT_STATS) · New master confidence map (MASTER_CONF) QC1 Parameters: FLATRMS FLATRATIO_MED FLATRATIO_RMS GAIN_CORRECTION VIRCAM Functions Used: vircam_imcombine, vircam_mkconf, vircam_darkcor, vircam_lincor Fatal Error Conditions: · Null input frameset · Input frameset headers incorrect meaning that RAW and CALIB frames cannot be distinguished · No twilight flat frames in input frameset · No master dark frame in input frameset · Inability to save output products Non-fatal Error Conditions: · No master twilight flat. No ratio image formed · No master bad pixel map or confidence map. All pixels considered to be good. · No channel table in input frameset. No ratio image stats table or linearisation will be done. Conditions Leading To Dummy Products: · The twilight frame image extensions won't load · The detector for the current image extension is flagged dead. · All the dark corrected images are either above the over exposure threshold or just below the under exposure threshold. · Master dark extension won't load or is flagged as a dummy


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vircam_imcombine failed Master twilight flat image failed to load or flagged as a dummy Channel table fits extension failed to load or flagged as a dummy

7.8 vircam_mesostep_analyse
Name:

vircam_mesostep_analyse Purpose: Create a map of illumination corrections using a mesostep sequence of a standard stars Type: Detector calibration Input Data: · A series of exposures of a sparse secondary standard field that has been offset in a regular raster · Library master dark frame for the given exposure and integration time · Library master flat field for the given passband · Library confidence map for the given passband or a library bad pixel mask · Library fringe frame · Linearity channel table · Photometric calibration table · Persistence mask · Crosstalk table · Photometric standard data (through VIRCAM interface to 2MASS) Parameters: int ipix The minimum size of an object in pixels in order for that object not to be considered spurious. float thr The detection threshold measured in units of the mean background noise int icrowd If set, then the function will attempt to de-blend merged objects float rcore The core radius in pixels for the default profile fit. int nb The size in pixels of the grid squares used for background estimation char *path2mass The full path to the 2MASS catalogue FITS files int destripe If this is set, then the input images will be de-striped. Not recommended for images that are likely to contain very large extended objects. int skycor If this is set, then the input images are stacked with rejection to form a mean background map. This is normalised to zero median and


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subtracted off the input images. This is not recommended for images that are likely to contain extended sources. int nord_ The order of the polynomial surface to be fit Algorithm: · Process the observations by linearising, dark correction and flat fielding · Compute the zero-point of standard stars on of each of the exposures. · Divide the area of the detector into cells and bin each of the zeropoint calculations into these cells. · Work out a median zero point for each cell · Fit the zeropoint solutions to a 2d polynomial. · Evaluate the polynomial at the central grid points of each cell. · Write the illumination correction table. Outputs: · Illumination correction table (see 5.7) (ILLCOR_TAB) QC1 Parameters: ILLUMCOR_RMS VIRCAM Functions Used: vircam_darkcor, vircam_lincor, vircam_flatcor, vircam_defringe, vircam_persist, vircam_crosstalk, vircam_imcore, vircam_getstds, vircam_matchstds Fatal Error Conditions: · Null input frameset · Input frameset headers incorrect meaning that RAW and CALIB frames cannot be distinguished · No science frames in input frameset · Missing master calibration frames or unreadable extensions in input frameset · Inability to save output products Non-fatal Error Conditions: None Conditions Leading To Dummy Products: · Missing calibration images, calibration images that won't load or are flagged as dummy. · A detector has been signalled dead. · Processing routines fail.

7.9 vircam_persistence_analyse
Name:

vircam_persistence_analyse Purpose: Analyse an image of bright stars and subsequent dark exposures to compute the persistence decay rate Type:


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Detector calibration Input Data: · An observation of bright stars taken close to saturation · A master dark frame for the given integration time · A master flat field for the given passband · A master confidence map for the given passband · Linearity channel table · A series of dark exposures taken at regular time intervals afterwards Parameters: float thresh Detection threshold for object extraction Algorithm: · Process the observation by linearising, dark correction and flat fielding · Compute the flux and position of bright stars on an image. · Look on subsequent dark exposures at the same location and compute the flux. · Fit the flux vs. t curve to an exponential to work out the characteristic decay constant, 0 and the flux a zero time. Outputs: · Persistence decay time constant · Persistence fraction at zero time QC1 Parameters: PERSIST_DECAY PERSIST_ZERO VIRCAM Functions Used: vircam_darkcor, vircam_lincor, vircam_flatcor, vircam_defringe, vircam_imcore Fatal Error Conditions: · Missing master calibration frames · Missing master calibration tables · No dark frames available after star observation. Non-fatal Error Conditions: None

7.10 vircam_crosstalk_analyse
Name:

vircam_crosstalk_analyse Purpose: Analyse a series of images to work out the crosstalk matrix for all detector sections Type: Detector calibration Input Data:


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A series of exposures of a bright star. The star should be centred in each of the instrument's data channels. · Master flat and confidence map for the given passband · Master dark frame for the given exposure time · Channel table Parameters: float thresh Detection threshold for object extraction Algorithm: · Locate objects on each exposure. · Use channel table to predict location of crosstalk images of the bright star and locate the crosstalk image in the object catalogue. · Create crosstalk matrix from the ratio of the fluxes for a given channel combination. Outputs: · Crosstalk matrix as described in 5.6 (XTALK) QC1 Parameters: CROSS_TALK VIRCAM Functions Used: vircam_imcore Fatal Error Conditions: · Missing channel table or confidence map Non-fatal Error Conditions: None

7.11 vircam_jitter_microstep_process
Name:

vircam_jitter_microstep_process Purpose: Process a sequence of target data that may have been both jittered and microstepped. Type: Science Input Data: · A jittered and/or microstepped sequence of exposures of a target region. · Library mean dark frame for the given exposure and integration time. · Library mean flat field frame for the given passband · Library confidence map for the given passband or a library bad pixel mask · Library fringe frame · Linearity channel table · Readnoise/gain file · Photometric calibration table · Crosstalk matrix · Persistence mask


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· Astrometric standard data (through VIRCAM interface to 2MASS) · Photometric standard data (through VIRCAM interface to 2MASS) Parameters: int ipix The minimum size of an object in pixels in order for that object not to be considered spurious. float thr The detection threshold measured in units of the mean background noise int icrowd If set, then the function will attempt to de-blend merged objects float rcore The core radius in pixels for the default profile fit. int nb The size in pixels of the grid squares used for background estimation char path2mass The full path to the 2MASS catalogue FITS files int destripe If this is set, then the input images will be de-striped. Not recommended for images that are likely to contain very large extended objects. int skycor If this is set, then the input images are stacked with rejection to form a mean background map. This is normalised to zero median and subtracted off the input images. This is not recommended for images that are likely to contain extended sources. int savecat If set, then the catalogue generated during the astrometric and photometric calibration will be saved. Algorithm: · Remove crosstalk images · Process the images by linearising and removing dark current and flat fielding · De-fringe · Remove persistent images · Correct for striping and sky background · Work out microstep offsets using header information · Combine the images into super-frames by interleaving using the microstep offsets · Work out jitter offsets by cross-correlating stellar object positions on super-frame images · Combine the super-frame images with offsets into a single stacked image · Generate a catalogue of objects on the stacked image and do a morphological classification · Fit a WCS using astrometric standards that appear in the stacked image catalogue. Update the FITS headers of the stacked image as well as those of the super-frames and the single exposure images.


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Calculate photometric zero point using instrumental magnitudes, magnitudes of photometric standards, and illumination corrections. Apply illumination correction to catalogue

Outputs: · Single exposure images that corrected for linearity, dark current, flat field, stripes, sky, image persistence and crosstalk. A full WCS will appear in the header (SIMPLE_IMAGE) · Interleaved super-frame images from the above if microstepping has been done as part of the observing sequence. (INTERLEAVED_IMAGE) · Stacked jitter images from the super-frames. Full WCS and photometric zero point will appear in the FITS header. (JITTERED_IMAGE) · Associated confidence maps for each of the above output images. (CONFIDENCE_MAP) · Object catalogue in the form of a FITS table if the savecat parameter has been set (OBJECT_CATALOGUE) QC1 Parameters: FRINGE_RATIO SATURATION MEAN_SKY SKY_NOISE NOISE_OBJ IMAGE_SIZE APERTURE_CORR ELLIPTICITY MAGZPT MAGZERR MAGNZPT LIMITING_MAG WCS_DCRVAL1 WCS_DCRVAL2 WCS_DTHETA WCS_SCALE WCS_SHEAR WCS_RMS VIRCAM Functions Used: vircam_darkcor, vircam_lincor, vircam_flatcor, vircam_defringe, vircam_persist, vircam_matchxy, vircam_crosstalk, vircam_imcore, vircam_getstds, vircam_platesol, vircam_matchstds, vircam_imdither, vircam_photcal Fatal Error Conditions: · Null input frameset · Input frameset headers incorrect meaning that RAW and CALIB frames cannot be distinguished · No science frames in input frameset · Missing master calibration frames or unreadable extensions in input frameset


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· Inability to save output products Non-fatal Error Conditions: None Conditions Leading To Dummy Products: · Missing calibration images, calibration images that won't load or are flagged as dummy. · A detector has been signalled dead. · Processing routines fail.

7.12 vircam_standard_process
Name:

vircam_standard_process Purpose: Process a sequence of photometric standard data that may have been both jittered and microstepped. Type: Science Input Data: · A jittered and/or microstepped sequence of exposures of a target region. · Library mean dark frame for the given exposure and integration time. · Library mean flat field frame for the given passband · Library confidence map for the given passband or a library bad pixel mask · Library fringe frame · Linearity channel table · Readnoise/gain file · Photometric calibration table · Crosstalk matrix · Persistence mask · Astrometric standard data (through VIRCAM interface to 2MASS) · Photometric standard data (through VIRCAM interface to 2MASS and a second source if requested) Parameters: int ipix The minimum size of an object in pixels in order for that object not to be considered spurious. float thr The detection threshold measured in units of the mean background noise int icrowd If set, then the function will attempt to de-blend merged objects float rcore The core radius in pixels for the default profile fit. int nb The size in pixels of the grid squares used for background estimation char *path2mass


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The full path to the 2MASS catalogue FITS files char *catpath The full path to a second photometric catalogue char *catname The name of the second photometric catalogue int destripe If this is set, then the input images will be de-striped. Not recommended for images that are likely to contain very large extended objects. int skycor If this is set, then the input images are stacked with rejection to form a mean background map. This is normalised to zero median and subtracted off the input images. This is not recommended for images that are likely to contain extended sources. int savecat If set, then the catalogue generated during the astrometric and photometric calibration will be saved. Algorithm: · Remove crosstalk images · Process the images by linearising and removing dark current and flat fielding · De-fringe · Remove persistent images · Correct for striping and sky background · Work out microstep offsets using header information · Combine the images into super-frames by interleaving using the microstep offsets · Work out jitter offsets by cross-correlating stellar object positions on super-frame images · Combine the super-frame images with offsets into a single stacked image · Generate a catalogue of objects on the stacked image and do a morphological classification · Fit a WCS using astrometric standards that appear in the stacked image catalogue. Update the FITS headers of the stacked image as well as those of the super-frames and the single exposure images. · Calculate photometric zero point using instrumental magnitudes, magnitudes of photometric standards, and illumination corrections. · If a second photometric catalogue is specified, the redo the photometric zero point. · Apply illumination correction to catalogue
Outputs: · Single exposure images that corrected for linearity, dark current, flat field, stripes, sky, image persistence and crosstalk. A full WCS will appear in the header (SIMPLE_IMAGE) · Illumination correction table (ILLCOR_TAB)


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Interleaved super-frame images from the above if microstepping has been done as part of the observing sequence. (INTERLEAVED_IMAGE) · Stacked jitter images from the super-frames. Full WCS and photometric zero point will appear in the FITS header. (JITTERED_IMAGE) · Associated confidence maps for each of the above output images. (CONFIDENCE_MAP) · Object catalogue in the form of a FITS table if the savecat parameter has been set (OBJECT_CATALOGUE) QC1 Parameters: FRINGE_RATIO SATURATION MEAN_SKY SKY_NOISE NOISE_OBJ IMAGE_SIZE APERTURE_CORR ELLIPTICITY MAGZPT MAGZERR MAGNZPT LIMITING_MAG ILLUMCOR_RMS WCS_DCRVAL1 WCS_DCRVAL2 WCS_DTHETA WCS_SCALE WCS_SHEAR WCS_RMS ZPT_2MASS ZPT_STDS VIRCAM Functions Used: vircam_darkcor, vircam_lincor, vircam_flatcor, vircam_defringe, vircam_persist, vircam_matchxy, vircam_crosstalk, vircam_imcore, vircam_getstds, vircam_platesol, vircam_matchstds, vircam_imdither, vircam_photcal, vircam_illum Fatal Error Conditions: · Null input frameset · Input frameset headers incorrect meaning that RAW and CALIB frames cannot be distinguished · No science frames in input frameset · Missing master calibration frames or unreadable extensions in input frameset · Inability to save output products Non-fatal Error Conditions: None Conditions Leading To Dummy Products:


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Missing calibration images, calibration images that won't load or are flagged as dummy. A detector has been signalled dead. Processing routines fail.


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Validation tests

Validation procedures will be developed for each function defined in chapter 6 and every recipe defined in chapter 7. In the case of the latter data described later in this chapter will be used to validate results. In the case of the former, recipe plugins have been written to test each function individually. What appears in this chapter is the set of test recipes as they currently stand, rather than the complete planned set. As these recipes may prove useful in themselves, these will be installed in the same tree as the reduction recipes. A very brief discussion of each test recipe is included in the next sections. As in previous recipe descriptions, each recipe has a parameter ext which is used to tell the recipe which of the FITS extensions you want to process. This parameter has been left of the parameter list for each recipe for the sake of brevity. The final section describes the test data that will be provided.

8.1 vircam_darkcor
Name:

vircam_darkcor Purpose: Test the function vircam_darkcor (section 6.2) by subtracting a dark frame from an input science frame. Input Data: · A raw science frame (required, SCIENCE_IMAGE) · Master dark frame of the same exposure parameters as above (required, MASTER_DARK) Parameters: float darkscl The factor by which to scale the dark frame before subtracting.

8.2 vircam_defringe
Name:

vircam_defringe Purpose: Test the function vircam_defringe (section 6.3) iteratively fitting a fringe pattern and subtracting it out. Input Data: · A raw science frame (required, SCIENCE_IMAGE) · A master fringe frame (required, MASTER_FRINGE) · Master mask in the form of a confidence map or a bad pixel mask (optional, MASTER_CONF or MASTER_BPM) Parameters: int nbsize The size of the smoothing cells used in the large scale background removal algorithm


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8.3 vircam_destripe
vircam_destripe Purpose: Test the function vircam_destripe (section 6.4) by modelling the background stripes in an input image and subtracting it out. Input Data: · A raw science frame (required, SCIENCE_IMAGE) · Master mask in the form of a confidence map or a bad pixel mask (optional, MASTER_CONF or MASTER_BPM) Parameters: None

8.4 vircam_flatcor
Name:

vircam_flatcor Purpose: Test the function vircam_flatcor (section 6.5) by dividing a flat field image into an input science frame. Input Data: · A science frame (required, SCIENCE_IMAGE). For best results, this should have been previously dark corrected. · Master twilight flat frame (required, MASTER_TWILIGHT_FLAT) Parameters: None

8.5 vircam_getstds
Name:

vircam_getstds Purpose: Test the function vircam_getstds (section 6.7) by extracting standard stars from the 2MASS catalogue that should appear on an input image. Input Data: · A science frame (required, SCIENCE_IMAGE). Parameters: char *catpath The full path to the 2MASS PSC FITS tables.

8.6 vircam_imcombine
Name:

vircam_imcombine Purpose: Test the function vircam_imcombine (section 6.9) by combining a list of input images into a single output image. Input Data:


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· A list of science frames (required, SCIENCE_IMAGE). Parameters: int comb Determines the type of combination that is done to form the output map. Can take the following values 1. The output pixels are medians of the input pixels 2. The output pixels are means of the input pixels int scale Determines how the input data are scaled or offset before they are combined. Can take the following values: 0. No scaling or biasing 1. All input frames are biased additively to bring their backgrounds to a common median level. 2. All input frames are biased multiplicatively to bring their backgrounds to a common median level. 3. All input frames are scaled to a uniform exposure time and then additively corrected to bring their backgrounds to a common median level. int xrej If set, then an extra rejection cycle will be run. int thr The rejection threshold in numbers of background sigmas.

8.7 vircam_imcore
Name:

vircam_imcore Purpose: Test the function vircam_imcore (section 6.10) by extracting objects from a science frame and writing them to a FITS table. Input Data: · A science frame (required, SCIENCE_IMAGE). · An appropriate confidence map (required, CONFIDENCE_MAP or MASTER_CONF) Parameters: int ipix The minimum size of an object in pixels in order for that object not to be considered spurious. float thr The detection threshold measured in units of the mean background noise int icrowd If set, then the function will attempt to de-blend merged objects float rcore The core radius in pixels for the default profile fit. int nb The size in pixels of the grid squares used for background estimation. int cattype


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The output catalogue type. This can be: 1. The 32 column INT Wide Field Camera format 2. The 80 column WFCAM format 3. A very minimal format which is just fine if all you want is positions 4. An object mask NB: option 2 corresponds to the catalogues described in section 5.12.

8.8 vircam_imdither
Name:

vircam_imdither Purpose: Test the function vircam_imdither (section 6.11) by dithering a list of input files and their associated confidence maps into a single output map Input Data: · A list of science frames (required, SCIENCE_IMAGE). · A list of confidence maps (required, CONFIDENCE_MAP or MASTER_CONF) Parameters: None

8.9
Name:

vircam_interleave

vircam_interleave Purpose: Test the function vircam_interleave (section 6.12) by interleaving a set of input science frames Input Data: · A set of science frame (required, SCIENCE_IMAGE) · An appropriate set of confidence maps (required, MASTER_CONF) Parameters: None

8.10 vircam_lincor
Name:

vircam_lincor Purpose: Test the function vircam_lincor (section 6.13) by linearising a science frame. Input Data: · A science frame (required, SCIENCE_IMAGE). For best results, this should have been previously dark corrected and flat field. · A channel table (required, CHANNEL_TABLE) Parameters: None


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8.11 vircam_matchstds
vircam_matchstds Purpose: Test the function vircam_matchstds (section 6.14) by matching an object catalogue with a standards table. Input Data: · An object catalogue (required, OBJECT_CATALOGUE). · An extracted standards catalogue (required, STANDARDS_TABLE) Parameters: None

8.12 vircam_matchxy
Name:

vircam_matchxy Purpose: Test the function vircam_matchxy (section 6.15) by matching two object catalogues and working out the Cartesian positional difference. Input Data: · Two object catalogues (required, OBJECT_CATALOGUE). Parameters: None

8.13 vircam_mkconf
Name:

vircam_mkconf Purpose: Test the function vircam_mkconf (section 6.16) by creating a confidence map from a master flat and a master bad pixel mask. Input Data: · A master flat field (required, MASTER_TWILIGHT_FLAT). · A master bad pixel mask or master confidence map (required, MASTER_BPM or MASTER_CONF) Parameters: None

8.14 vircam_platesol
Name:

vircam_platesol Purpose: Test the function vircam_platesol (section 6.19) by fitting a plate constant model to a matched standards catalogue. Input Data: · A science frame with an initial WCS (required, SCIENCE_IMAGE)


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A matched standards table of objects on the science frame (required, MATCHED_STANDARDS_TABLE). Parameters: int nconst The number of plate constants to fit. This must be either 4 or 6. int shiftan If this is set, then the position of the tangent point will be moved to take poor telescope pointing into account.

8.15 Validation Test Data
Test data will be provided for all of these validation procedures. In some cases this will consist of laboratory test data using the real VISTA focal plane detectors. In others, data from other instruments, namely WFCAM will be made to look like VISTA data. Where nothing else is available, simulated data will be generated and wrapped to look like VISTA data files. In the table below we give a list of the test data files that will be available for use in the validation procedures. Each FITS file will contain data for all sixteen detectors. The `rich_field' files will consist of observations of a medium rich stellar field, which can be used for many of the validation tests we require. The series will be a 5 point jitter series, where each jitter point is also a 4 point microstep sequence. Included in the test suite will be files that can be used in comparison with output from the test procedures. These will be monitored to ensure that: · the image data arrays and table columns all contain exactly the same data · a selection of relevant FITS header keywords have been created and are consistent with the test output files. · output QC1 parameters match the known values from the test suite. A selection of SOF files will also be included to insure that the tests are always done using the same files. Below is a list of test data to be expected in the test data suite.
datafile bpm.fits chantab.fits dark_after_richXX.fits comment A bad pixel mask The channel table (5.2) A series of dark frames taken after the last rich_fieldXX frame. A list of dark frames with the same exposure time as rich_fieldXX A series of dark frames with exposure times the same as those for domeflatXX_raw.fits A series of dome flat exposures done with a series of exposure times with constant illumination. These have been dark corrected. A series of dome flat exposures done with a series of exposure times with constant illumination. These have not been dark corrected. A mean fringe frame

darkXX.fits darkXX_exp.fits domeflatXX.fits domeflatXX_raw.fits fringe.fits


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An illumination correction table for rich_field01.fits Matched standards table of objtab01.fits matched to stds_2mass.fits meanconf.fits A confidence map arising from twiflatXX.fits. meandark.fits A mean dark frame formed from the list darkXX.fits meandomeflat.fits A mean dome flat formed from domeflatXX.fits meanreset.fits A mean reset frame formed from the list resetXX.fits meantwiflat.fits A mean twilight flat field frame formed from twiflatXX.fits objtab01.fits The object tables for rich_field01_sig.fits and objtab02.fits rich_field02_sig.fits for a given set of extraction parameters persistmask.fits A persistence mask for the rich_fieldXX series resetXX.fits A list of reset frames rich_comb.fits The rich_field_sig series combined with no coordinate offsets rich_comb_conf.fits The confidence map formed from combining rich_field_sig files with no coordinate offsets. rich_field01_dark.fits The first rich_field file ­ dark corrected using meandark.fits rich_field01_flat.fits The first rich_field file ­ flat fielded using meantwiflat.fits rich_field01_lin.fits The first rich field file ­ linearised using lchantab.fits rich_field01_sigf.fits The first rich field file with linearity, dark, and flat corrections applied rich_fieldXX.fits A raw microstep and jitter sequence of a rich photometric standard field rich_fieldXX_meso.fits A raw meso-stepped series of the rich_field region. rich_fieldXX_sig.fits The rich field series with linearity, dark, flat and fringe corrections applied rich_stack.fits A stack of rich_fieldXX_sig.fits series. rich_stack_conf.fits A confidence map formed from stacking the rich_fieldXX_sig.fits series rich_super.fits A super frame of the first microstep sequence in the rich_fieldXX_sig series. rich_super_conf.fits The confidence map formed from interleaving the first microstep sequence in the rich_fieldXX_sig series. stds_2mass.fits A list of 2mass standards that appear on rich_field01.fits twiflatXX.fits A list of twilight flat field frames in one colour. These have been linearity and dark corrected twiflatXX_raw.fits A list of raw twilight flat field frames in one colour xtalk.fits A full crosstalk matrix
Table 8-1 Description of test data files

In the tables below we give a list of each of the VIRCAM functions and plugins from chapters 6 and 7 and the input files required from the test data suite. The files in the column `output test files' will be used in to test consistency of result with the output of each function or plugin.
function vircam_crosstalk input test files rich_field01.fits output test files xtalk.fits


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rich_field01.fits meandark.fits vircam_defringe rich_field01_sigf.fits fringe.fits vircam_flatcor rich_field01.fits meantwiflat.fits vircam_genlincur domeflatXX.fits chantab.fits vircam_getstds rich_field01.fits vircam_illum rich_field01_sig.fits vircam_imcombine rich_fieldXX_sig.fits meanconf.fits vircam_imcore rich_field01_sig.fits meanconf.fits vircam_imstack rich_fieldXX_sig.fits vircam_interleave vircam_lincor vircam_matchstds vircam_matchxy vircam_mkconf vircam_persist vircam_photcal vircam_platesol rich_fieldXX_sig.fits

rich_field01_dark.fits rich_field01_sig.fits rich_field01_flat.fits lchantab.fits stds_2mass.fits illumtab.fits rich_comb.fits rich_comb_conf.fits objtab01.fits rich_stack.fits rich_stack_conf.fits rich_super.fits rich_super_conf.fits rich_field01_lin.fits

rich_field01.fits lchantab.fits objtab01.fits match_stds.fits stds_2mass.fits objtab01.fits objtab02.fits twiflatXX.fits meanconf.fits rich_fieldXX_sig.fits dark_after_richXX.fits rich_stack.fits stds_2mass.fits rich_field01_sig.fits match_stds.fits

Table 8-2 Files to be used to test each vircam function

plugin vircam_reset_combine vircam_dark_combine vircam_dome_flat_combine vircam_detector_noise

vircam_linearity_analyse vircam_twilight_combine

input test files resetXX.fits darkXX.fits domeflatXX.fits domeflatXX.fits darkXX.fits domeflatXX_raw.fits darkXX_exp.fits chantab.fits twiflatXX_raw.fits meandark.fits lchantab.fits bpm.fits

output test files meanreset.fits meandark.fits meandomeflat.fits

lchantab.fits bpm.fits meantwiflat.fits meanconf.fits


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vircam_mesostep_analyse

rich_fieldXX_meso.fits meandark.fits meantwiflat.fits lchantab.fits fringe.fits vircam_persistence_analyse rich_fieldXX.fits meandark.fits meantwiflat.fits lchantab.fits meanconf.fits vircam_crosstalk_analyse rich_fieldXX.fits meandark.fits meantwiflat.fits lchantab.fits meanconf.fits vircam_sky_flat_combine rich_fieldXX.fits meandark.fits meantwiflat.fits fringe.fits lchantab.fits meanconf.fits bpm.fits vircam_jitter_microstep_process rich_fieldXX.fits meandark.fits meantwiflat.fits fringe.fits lchantab.fits meanconf.fits xtalk.fits persistmask.fits vircam_standard_process rich_fieldXX.fits meandark.fits meantwiflat.fits fringe.fits lchantab.fits meanconf.fits xtalk.fits persistmask.fits

xtalk.fits

rich_comb.fits rich_comb_conf.fits

rich_stack.fits rich_stack_conf.fits

rich_stack.fits rich_stack_conf.fits illumtab.fits

Table 8-3 Files to use in testing each vircam plugin


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Development Plan

Following [AD1] the DRL development is summarised in Table 9-1. In keeping with the fact that VISTA will (initially) be a single-instrument telescope, and so will essentially have a single commissioning period (no COM2), milestone 5 is omitted in order to keep the numbering consistent with general VLT planning. Act ID M-02 Milestone FDR PAE Timeline -4w -6m Deliv. ID DR2 Deliverables This document Data Reduction Library prototype with some basic dome-flat capability; will test instrument simulation datainterface compatibility. Data Reduction Library v0.1 Including: all basic planned functionality such that laboratory data from the instrument may be pipelined. Data Reduction Library v0.5 Including: bug fixes found at PAE plus any new (previously unplanned) functionality required as a result of PAE detector characterisation. Data Reduction Library v1.0 Including: more bug fixes and any refinements and additions to analysis required as a result of experience gained with real commissioning data. Data Reduction Library v1.y Including: more of above, and feedback from early science users. Final version this document

M-03

PAE

-4w

DR3

M-04

COM1

-4w

DR4

M-06

PAC

-4w

DR6

M-09

SO1

+8w

DR11

+8w

DR11

Table 9-1 Development Schedule


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10 Appendix: QC1 Parameters
#******************************************************************************* # E.S.O. VISTA project # # "@(#) $Id: dicVIRCAM_QC.txt,v 0.8 2004/07/29 12:05:28 vltsccm Exp $" # # VIRCAM_QC dictionary # # who when what #------------------------------------------------------------# pbunclark 2004-10-05 Original # pbunclark 2004-11-19 Many clarifications # DID parameter added # POINTING -> WCS set # SEEING -> IMAGE SIZE # mji 2004-11-22 Updated comments and descriptions # and rationalized order # jrl 2004-12-08 add FRINGE_RMS, ILLUMCOR_RMS # jrl 2004-12-13 change FRINGE_RMS to FRINGE_RATIO, # add LINFITQUAL # psb 2005-12-13 RESETVAR changed to RESETRMS, improved # comments on DARKRMS, PARTICLE_RATE & RESETRMS # jrl 2005-12-19 add RESETDIFF_RMS DARKDIFF_RMS # jpe 2006-02-03 improve couple of descriptions. # jrl 2006-03-24 add RESETDIFF_MED, DARKDIFF_MED, # FLATRATIO_MED, FLATRATIO_RMS # jrl 2006-06-05 add MAGZPT, MAGZERR and MAGNZPT # psb 2006-06-06 add QC.RESET_MED & QC.DARKMED # jrl 2006-11-10 fixed a few typos and changed entries to a more # logical order. Removed SKY_RESET_ANOMALY. # # NAME # ESO-DFS-DIC.VIRCAM_QC - Data Interface Dictionary for VIRCAM Quality # control (level 1) parameters. #------------------------------------------------------------------------------Dictionary Name: ESO-VLT-DIC.VIRCAM_QC Scope: ESO VISTA VIRCAM Source: ESO VLT Version Control: @(#) $Id: 0.8 $ Revision: $Revision: 0.9 $ Date: 2006-11-13 Status: Development Description: VIRCAM Quality-Control Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description: Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description: Parameter Name: Class: Context: Type: Value Format: QC DID header process string %30s Data dictionary for VIRCAM QC. Name/version of ESO DID to which QC keywords comply. QC RESETMED header process double %f median reset level median reset level QC RESETRMS header process double %f


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RMS noise in combined reset frame. variation is defined here as the Gaussian equivalent MAD ie. 1.48*median-of-absolute-deviation from unity after normalising by median level ie. measuring the RMS reset level variation. The RMS can later be compared with library values for troubleshooting problems. QC RESETDIFF_MED header process double %f adu Median new-library reset frame [adu]. Measure the median of the difference of a new mean reset frame and a library reset frame. QC RESETDIFF_RMS header process double %f adu [adu] RMS new-library reset frame measure the RMS of the difference of a new mean reset frame and a library reset frame. QC DARKMED header process double %f median dark counts median counts in dark frames. QC DARKRMS header process double %f adu RMS noise of combined dark frame [adu]. RMS is defined here as the Gaussian equivalent MAD ie. 1.48*median-of-absolute-deviation from median The RMS can later be compared with library values for darks of the same integration and exposure times. QC DARKDIFF_MED header process double %f adu Median new-library dark frame [adu]. Measure the median of the difference of a new mean dark frame and a library reset frame. QC DARKDIFF_RMS header process double %f adu [adu] RMS new-library dark frame measure the RMS of the difference of a new mean dark frame and a library dark frame. QC PARTICLE_RATE header

Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description: Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description: Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description: Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description:

Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description: Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description: Parameter Name: Class:


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process double %f count/s/detector cosmic ray/spurion rate [count/s/detector]. average no. of pixels rejected during combination of dark frames, used to give an estimate of the rate of cosmic ray hits for each detector. This can later be compared with previous estimates and monitored. QC DARKCURRENT header process double %f adu/sec average dark current on frame [adu/sec]. measured using the median of the pixel values, can later be compared similar darks for trends QC FLATRMS header process double %f fraction RMS flatfield pixel sens per detector [fraction]. RMS is defined here as the Gaussian equivalent MAD ie. 1.48*median-of-absolute-deviation from unity after normalising by median level ie. measuring the RMS sensitivity variation. The RMS can later be compared with library values for troubleshooting problems. significantly with time. QC FLATRATIO_MED header process double %f scalar Median new/library flat frame [scalar]. Measure the median of the ratio of a new mean flat frame and a library flat frame. QC FLATRATIO_RMS header process double %f scalar RMS new/library flat frame [scalar]. Measure the RMS of the ratio of a new mean flat frame and a library flat frame. QC GAIN_CORRECTION header process double %f scalar detector median flatfield/global median [scalar]. the ratio of median counts in a mean flat exposure for a given detector relative to the ensemble defines the internal gain correction for the detector These internal relative detector gain corrections should be stable with time. QC READNOISE header

Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description: Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description:

Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description: Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description: Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description:

Parameter Name: Class:


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process double %f electron readnoise [electron]. measured from the noise properties of the difference in two consecutive dark frames, using a MAD estimator as above for robustness against spurions. The noise properties of each detector should remain stable so long as the electronics/micro-code have not been modified. QC GAIN header process double %f e/ADU gain [e/ADU]. determined from pairs of darks and flatfields of the same exposure/integration time and illumination by comparing the measured noise properties with the expected photon noise contribution. The gain of each detector should remain stable so long as the electronics/micro-code have not been modified. QC LINEARITY header process double %f percentage percentage average non-linearity [percentage]. derived from measured non-linearity curves for each detector interpolated to 10k counts (ADUs) level. Although all infrared systems are non-linear to some degree, the shape and scale of the linearity curve for each detector should remain constant. A single measure at 20k counts can be used to monitor this although the full linearity curves will need to be examined quarterly [TBC] to look for more subtle changes. QC LINFITQUAL header process double %f RMS fractional error in linearity fit Derived by applying the linearity coefficients to the image data that were used to measure them. This is the RMS of the residuals of the linearised data normalised by the expected linear value QC BAD_PIXEL_STAT header process double %f scalar fraction of bad pixels/detector [scalar]. determined from the statistics of the pixel distribution from the ratio of two flatfield sequences of significantly different average count levels. The fraction of bad pixels per detector (either hot or cold) should not change QC WCS_DCRVAL1

Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description:

Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description:

Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description:

Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description:

Parameter Name:


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header process double %e deg actual WCS zero point X - raw header value [deg]. measure of difference between dead-reckoning pointing and true position of the detector on sky. Derived from current polynomial distortion model and 6-constant detector model offset. QC WCS_DCRVAL2 header process double %e deg actual WCS zero point Y - raw header value [deg]. measure of difference between dead-reckoning pointing and true position of the detector on sky. Derived from current polynomial distortion model and 6-constant detector model offset. QC WCS_DTHETA header process double %e deg actual WCS rotation PA - raw PA header value [deg]. measure of difference between dead-reckoning PA and true position angle of the detector. Derived from current polynomial distortion model and 6-constant detector model effective rotation term. QC WCS_SCALE header process double %e deg/pixel measured WCS plate scale per detector [deg/pixel]. measure of the average on-sky pixel scale of detector after correcting using current polynomial distortion model QC WCS_SHEAR header process double %e deg power of cross-terms in WCS solution [deg]. measure of WCS shear after normalising by plate scale and rotation, expressed as an equivalent distortion angle. Gives a simple measure of distortion problems in WCS solution. QC WCS_RMS header process double %e arcsec robust RMS of WCS solution for each detector [arcsec]. robust average of residuals from WCS solution for each detector. Measure of integrity of WCS solution. QC MEAN_SKY header process double %f ADU

Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description:

Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description:

Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description: Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description:

Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description: Parameter Name: Class: Context: Type: Value Format: Unit:


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mean sky level [ADU]. computed using a clipped median for each detector Sky levels (perhaps not at Ks) should vary smoothly over the night. Strange changes in values may indicate a hardware fault. QC SKY_NOISE header process double %f ADU RMS sky noise [ADU]. computed using a MAD estimator with respect to median sky after removing large scale gradients. The sky noise should be a combination of readout-noise, photon-noise and detector quirks. Monitoring the ratio of expected noise to measured provides a system diagnostic at the detector level. QC SATURATION header process double %f ADU saturation level of bright stars [ADU]. determined from maximum peak flux of detected stars from exposures in a standard bright star field. The saturation level*gain is a check on the full-well characteristics of each detector. QC NOISE_OBJ header process integer %d number number of classified noise objects per frame [number]. measured using an object cataloguer combined with a morphological classifier. The number of objects classified as noise from frame-to-frame should be reasonably constant; excessive numbers indicate a problem. QC IMAGE_SIZE header process double %f arcsec mean stellar image FWHM [arcsec]. measured from the average FHWM of stellar-classified images of suitable signal:to:noise. The seeing will obviously vary over the night with time, wavelength (filter) and as airmass^0.6. This variation should be predictable given local site seeing measures. A comparison with the expected value can be used as an indication of poor guiding, poor focus or instrument malfunction. QC APERTURE_CORR header process double %f mag 2 arcsec [mag] diam aperture flux correction. the aperture flux correction for stellar images due to flux falling outside the aperture. Determined using a curve-of-growth of a series of fixed-size apertures.

Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description:

Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description:

Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description:

Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description:

Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description:


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Alternative simple measure of image profile properties, particularly the presence of extended PSF wings, as such monitors optical properties of system; also required for limiting magnitude computations. Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description: QC ELLIPTICITY header process double %f scalar mean stellar ellipticity [scalar]. the detected image intensity-weighted second moments will be used to compute the average ellipticity of suitable signal:to:noise stellar images. Shot-noise causes even perfectly circular stellar images to have non-zero ellipticity but more significant values are indicative of one of: optical, tracking and autoguiding, or detector hardware problems. QC MAGZPT header process double %f mag Photometric zero point [mag]. A measure of the photometric zero point using an aperture of 1* the core radius. QC MAGZERR header process double %f mag Photometric zero point error [mag]. A measure of the RMS photometric zero point error using an aperture of 1* the core radius. QC MAGNZPT header process double %f Number of stars in zero point calc. The number of stars on this image used to calculate the photometric zeropoint. QC ZPT_2MASS header process double %f mag 1st-pass photometric zeropoint [mag]. the magnitude of a star that gives 1 detected ADU/s (or e-/s) for each detector, derived using 2MASS comparison stars for every science observation. This is a first pass zero-point to monitor gross changes in throughput. Extinction will vary over a night, but detector to detector variations are an indication of a fault. QC ZPT_STDS header process double %f mag photometric zeropoint [mag]. the magnitude of a star that gives 1 detected ADU/s

Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description: Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description: Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description: Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description:

Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description:


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(or e-/s) for each detector, derived from observations of VISTA standard star fields. Combined with the trend in long-term system zero-point properties, the ensemble "average" zero-point directly monitors extinction variations (faults/mods in the system notwithstanding) The photometric zeropoints will undoutbedly vary (slowly) over time as a result of the cleaning of optical surfaces etc. Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description: QC LIMITING_MAG header process double %f mag limiting mag ie. depth of exposure [mag]. estimate of 5-sigma limiting mag for stellar-like objects for each science observation, derived from QCs ZPT_2MASS, SKY_NOISE, APERTURE_CORR. Can later be compared with a target value to see if main survey requirements (ie. usually depth) are met. QC PERSIST_DECAY header process double %f s mean exponential time decay constant [s]. the decay rate of the persistence of bright images on subsequent exposures will be modelled using an exponential decay function with time constant tau. Requires an exposure on a bright star field followed a series of darks. QC PERSIST_ZERO header process double %f fractional persistence at T0 (extrapolated). determined from the persistence decay behaviour from exponential model fitting. Requires an exposure on a bright star field followed a series of darks (as above) QC CROSS_TALK header process double %f scalar average values for cross-talk component matrix [scalar]. determined from presence of +ve or -ve ghost images on other channels/detectors using exposures in bright star fields. Potentially a fully populated 256x256 matrix but likely to be sparsely populated with a small number of non-zero values of band-diagonal form. This QC summary parameter is the average value of the modulus of the off-diagonal terms. Values for the cross-talk matrix should be very stable with time, hardware modifications notwithstanding. QC FRINGE_RATIO header process double %f scalar [scalar] Ratio of sky noise before/after fringe fit A robust estimate of the background noise is done before the first fringe fitting pass.

Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description:

Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description:

Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description:

Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description:


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Once the last fringe fit is done a final background noise estimate is done. This parameter is the ratio of the value before fringe fitting to the final value after defringing. Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description: QC ILLUMCOR_RMS header process double %f mag [mag] RMS in illumination correction The RMS of the illumination correction over all of the frame.

The above dictionary is illustrated as a FITS header extract as it will appear in the perdetector extension header:
HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO QC QC QC QC QC QC QC QC QC QC QC QC QC QC QC QC QC QC QC QC QC QC QC QC QC QC QC QC QC QC QC QC QC QC QC QC QC QC QC QC QC QC QC QC DID = 'ESO-VLT-DIC.VIRCAM_QC ' / Data dictionar RESETMED = 0.000000 / median reset level RESETRMS = 0.000000 / RMS noise in combined reset fra RESETDIFF_MED= 0.000000 / Median new-library reset frame RESETDIFF_RMS= 0.000000 / [adu] RMS new-library reset fra DARKMED = 0.000000 / median dark counts DARKRMS = 3.456000 / RMS noise of combined dark fram DARKDIFF_MED = 0.000000 / Median new-library dark frame [ DARKDIFF_RMS = 0.000000 / [adu] RMS new-library dark fram PARTICLE_RATE= 20.500000 / cosmic ray/spurion rate [count/ DARKCURRENT = 200.000000 / average dark current on frame [ FLATRMS = 0.000000 / RMS flatfield pixel sens per de FLATRATIO_MED= 0.000000 / Median new/library flat frame [ FLATRATIO_RMS= 0.000000 / RMS new/library flat frame [sca GAIN_CORRECTION= 0.950000 / detector median flatfield/globa READNOISE = 150.000000 / readnoise [electron]. GAIN = 1.600000 / gain [e/ADU]. LINEARITY = 0.030000 / percentage average non-linearit LINFITQUAL = 0.000000 / RMS fractional error in lineari BAD_PIXEL_STAT= 0.006000 / fraction of bad pixels/detector WCS_DCRVAL1 = 5.555550e-04 / actual WCS zero point X - raw h WCS_DCRVAL2 = -5.555500e-04 / actual WCS zero point Y - raw h WCS_DTHETA = 1.000000e-02 / actual WCS rotation PA - raw PA WCS_SCALE = 9.444400e-05 / measured WCS plate scale per de WCS_SHEAR = 1.000000e-04 / power of cross-terms in WCS sol WCS_RMS = 9.444400e-06 / robust RMS of WCS solution for MEAN_SKY = 12345.120000 / mean sky level [ADU]. SKY_NOISE = 2000.000000 / RMS sky noise [ADU]. SATURATION = 65535.000000 / saturation level of bright star NOISE_OBJ = 150 / number of classified noise obje IMAGE_SIZE = 0.500000 / mean stellar image FWHM [arcsec APERTURE_CORR= 0.456000 / 2 arcsec [mag] diam aperture fl ELLIPTICITY = 0.021100 / mean stellar ellipticity [scala MAGZPT = 0.000000 / Photometric zero point [mag]. MAGZERR = 0.000000 / Photometric zero point error [m MAGNZPT = 0.000000 / Number of stars in zero point c ZPT_2MASS = 26.500000 / 1st-pass photometric zeropoint ZPT_STDS = 26.400000 / photometric zeropoint [mag]. LIMITING_MAG = 24.567000 / limiting mag ie. depth of expos PERSIST_DECAY= 40.000000 / mean exponential time decay con PERSIST_ZERO = 0.800000 / fractional persistence at T0 (e CROSS_TALK = 1.000000 / average values for cross-talk c FRINGE_RATIO = 0.000000 / [scalar] Ratio of sky noise bef ILLUMCOR_RMS = 0.000000 / [mag] RMS in illumination corre


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The following table references the QC parameters with the functions and recipes where they are generated:
QC PARAMETER APERTURE_CORR FUNCTION imcore RECIPE jitter_microstep_process standard_process linearity_analyse crosstalk_analyse dark_combine dark_current dark_combine dark_combine dark_combine jitter_microstep_process standard_process dome_flat_combine twilight_combine dome_flat_combine twilight_combine dome_flat_combine twilight_combine jitter_microstep_process standard_process detector_noise twilight_combine mesostep_analyse standard_process jitter_microstep_process standard_process jitter_microstep_process standard_process linearity_analyse linearity_analyse jitter_microstep_process standard_process jitter_microstep_process standard_process jitter_microstep_process standard_process jitter_microstep_process standard_process jitter_microstep_process standard_process dark_combine persistence_analyse

BAD_PIXEL_STAT CROSS_TALK DARDIFF_MED DARKCURRENT DARKDIFF_RMS DARKMED DARKRMS ELLIPTICITY FLATRATIO_MED FLATRATIO_RMS FLATRMS FRINGE_RATIO GAIN GAIN_CORRECTION ILLUMCOR_RMS IMAGE_SIZE LIMITING_MAG LINEARITY LINFITQUAL MAGNZPT MAGZERR MAGZPT MEAN_SKY NOISE_OBJ PARTICLE_RATE PERSIST_DECAY

imcore

defringe

illum imcore photcal

photcal photcal photcal imcore imcore


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PERSIST_ZERO READNOISE RESETDIFF_MED RESETDIFF_RMS RESETRMS RESETMED SATURATION STRIPERMS SKY_NOISE WCS_DCRVAL1 WCS_DCRVAL2 WCS_DTHETA WCS_RMS WCS_SCALE WCS_SHEAR ZPT_2MASS ZPT_STDS

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imcore imcore platesol platesol platesol platesol platesol platesol platesol photcal

Table 10-1 The origin of QC Parameters


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11 Appendix: DRS Dictionary
################################################################################ # E.S.O. VISTA project # # "@(#) $Id: ESO-VLT-DIC.VIRCAM_DRS,v 0.1 2005/04/04 vltsccm Exp $" # # # VIRCAM_DRS dictionary # # who when what #------------------------------------------------------------# pbunclark 2005-04-04 Original # jrl 2005-04-15 various tidyups # jrl 2006-03-23 add BACKMED, corrections # jrl 2006-04-28 added CLASSIFD, THRESHOL, MINPIX and CROWDED # jrl 2006-06-05 modified photometric zeropoint entries and # added XOFFDITHER and YOFFDITHER. # jrl 2006-11-10 added FILTFWHM, STRIPECOR, STRIPERMS, NDITCOR, # SKYCOR, IMADUMMY. Rearranged entries into a # more logical order. Dictionary Name: ESO-VLT-DIC.VIRCAM_DRS Scope: DFS Source: ESO VLT Version Control: @(#) $Id: 0.1 $ Revision: 0.3 Date: 2006-11-13 Status: Development Description: VIRCAM Processing keywords #-----------------------------------------------------------------------------# General keywords # Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description: Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description: Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description: Parameter Name: Class: Context: Type: Value Format: Unit: DRS DID header PROCESS string %30s Data dictionary for VIRCAM DRS Name/version of ESO DID to which DRS keywords comply. DRS NDITCOR header PROCESS unknown %b Flag for NDIT correction If this is set, then the frame has been corrected to a value of NDIT=1. DRS DARKCOR header PROCESS string %s dark image The name of the dark image specified in darksrc DRS DARKSCL header PROCESS double %f


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Comment Format: Description: Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description: Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description: Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description: Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description: Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description: Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description:

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Dark scale factor The scale factor used in the dark subtractionon DRS FLATCOR header PROCESS string %s flat field image The name of the flat field image specified in flatsrc DRS LINCOR header PROCESS string %s Channel table The name of the channel table used in the linearisation DRS SKYCOR header PROCESS unknown %b Flag for sky correction If set, then a sky background subtraction has been done on this image. DRS STRIPECOR header PROCESS unknown %b Flag from stripe correction If set, then this image has been destriped. DRS STRIPERMS header PROCESS double %f adu [adu] RMS of removed stripes If destriping is done, then this is the RMS of the stripe pattern that was removed from the image DRS XOFFMICRO header PROCESS double %f X-pixels to microstep input image The number of pixels in X by which to microstep the current input image relative to the output grid. DRS YOFFMICRO header PROCESS double %f Y-pixels to microstep input image The number of pixels in Y by which to microstep the current input image relative to the output grid.

Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description:


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DRS XOFFDITHER header PROCESS double %f X-pixels to jitter input image The number of pixels in X by which to jitter the current input image relative to the output grid. DRS YOFFDITHER header PROCESS double %f Y-pixels to jitter input image The number of pixels in Y by which to jitter the current input image relative to the output grid. DRS PROVXXXX header PROCESS string %s Input A set that This file. file # of FITS keywords that lists the files were combined to form this output file. establishes the provenance of the output

Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description:

Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description:

Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description: Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description: Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description: Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description: Parameter Name: Class:

DRS SKYLEVEL header PROCESS double %f ADU [ADU] Mean sky level The mean sky level in the image DRS SKYNOISE header PROCESS double %f ADU [ADU] Mean sky noise The mean sky noise in the image DRS STDCRMS header PROCESS double %f arcsec [arcsec] RMS of the WCS fit The RMS of the WCS fit DRS NUMBRMS header PROCESS integer %d no. of stars in WCS fit Number of stars in the WCS fit DRS WCSRAOFF header


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PROCESS double %f arcsec [arcsec] diff in RA after proc. The equatorial coordinates of the central pixel of the image is calculated both before and after the plate solution is found. This is the difference in the RA (in arcseconds). DRS WCSDECOFF header PROCESS double %f arcsec [arcsec] diff in DEC after proc. The equatorial coordinates of the central pixel of the image is calculated both before and after the plate solution is found. This is the difference in the DEC (in arcseconds). DRS BACKMED header PROCESS double %f adu [adu] Background median value The most recent estimate of the background DRS CLASSIFD header PROCESS integer %d Catalogue has been classified. Set if the classification software has been run on this catalogue. DRS THRESHOL header PROCESS double %f adu [adu] Isophotal analysis threshold Isophotal analysis used in object detection. DRS MINPIX header PROCESS integer %d pixels [pixels] Minimum size for images Minimum number of pixels for an object to cover DRS CROWDED header PROCESS integer %d Crowded field analysis flag If set, then the deblending software has been used to extract the objects in this catalogue. DRS RCORE header PROCESS double

Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description:

Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description: Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description: Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description: Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description: Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description: Parameter Name: Class: Context: Type:


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Value Format: Unit: Comment Format: Description: Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description: Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description: Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description:

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%f pixels [pixels] Core radius The core radius. This is set to the approximate expected FWHM of all the stellar images DRS SEEING header PROCESS double %f pixels [pixels] The estimated seeing The seeing esimated from the stellar images on the current frame. DRS FILTFWHM header PROCESS double %f pixels [pixels] Smoothing kernel FWHM The FWHM of the smoothing kernel used in the object detection algorithm. DRS ZPIM1 header PROCESS double %f mag [mag] photometric zeropoint The calculated photometric zeropoint for stars on the current image only through an aperture of 1* the core radius. DRS ZPSIGIM1 header PROCESS double %f mag [mag] RMS in photometric zeropoint The calculated RMS in photometric zeropoint for stars on the current image only through an aperture of 1* the core radius. DRS ZPIM2 header PROCESS double %f mag [mag] photometric zeropoint The calculated photometric zeropoint for stars on the current image only through an aperture of 2* the core radius. DRS ZPSIGIM2 header PROCESS double %f mag [mag] RMS in photometric zeropoint The calculated RMS in photometric zeropoint for stars on the current image only through an aperture of 2* the core radius. DRS LIMIT_MAG1 header PROCESS

Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description:

Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description:

Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description:

Parameter Name: Class: Context:


VISTA Data Flow System
Type: Value Format: Unit: Comment Format: Description: Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description: Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description: Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description:

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double %f mag [mag] Limiting magnitude 1*core radius The calculated 5 sigma limiting magnitude through an aperture of 1* the core radius DRS LIMIT_MAG2 header PROCESS double %f mag [mag] Limiting magnitude 2*core radius The calculated 5 sigma limiting magnitude through an aperture of 2* the core radius DRS MAGNZPTIM header PROCESS integer %d Number of stars used photometric zeropoint calc.(h) The number of stars used to calculate the photometric zeropoint for this image only. DRS ZPALL1 header PROCESS double %f mag [mag] photometric zeropoint The calculated photometric zeropoint for stars on all the images reduced together through an aperture of 1* the core radius. DRS ZPSIGALL1 header PROCESS double %f mag [mag] RMS in photometric zeropoint The calculated RMS in photometric zeropoint for stars on all the images reduced together through an aperture of 1* the core radius. DRS ZPALL2 header PROCESS double %f mag [mag] photometric zeropoint The calculated photometric zeropoint for stars on all the images reduced together through an aperture of 2* the core radius. DRS ZPSIGALL2 header PROCESS double %f mag [mag] RMS in photometric zeropoint The calculated RMS in photometric zeropoint for stars on all the images reduced together through an aperture of 2* the core radius. DRS MAGNZPTALL header

Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description:

Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description:

Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description:

Parameter Name: Class:


VISTA Data Flow System
Context: Type: Value Format: Unit: Comment Format: Description: Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description: Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description: Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description: Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description: Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description: Parameter Name: Class: Context: Type: Value Format: Unit: Comment Format: Description: Parameter Name: Class: Context: Type: Value Format:

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PROCESS integer %d Number of stars used photometric zeropoint calc.(h) The number of stars used to calculate the photometric zeropoint for all the images reduced together. DRS IMADUMMY header PROCESS unknown %b Flag for dummy image/table If this is set, then the image/table contained in this particular HDU is a dummy product. DRS FLATIN header PROCESS string %s flat field used The name of the flat field frame that was used to create this confidence map DRS BPMIN header PROCESS string %s bad pixel map used The name of the bad pixel mask image that was used to create this confidence map DRS PERMASK header PROCESS string %s persistence mask used The name of the persistence mask image that was used to create this confidence map DRS XTCOR header PROCESS string %s Crosstalk matrix table Name of the crosstalk matrix table used to process this image DRS FRINGEi header PROCESS string %s Fringe file of nth pass The name of the fringe file used in the nth defringing pass DRS FRNGSCi header PROCESS double %f


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scale factor nth defringe pass The scale factor for the nth defringing pass

12 Appendix: Raw FITS Header
SIMPLE = T / Standard FITS format (NOST-100.0) BITPIX = 8 / # of bits storing pix values NAXIS = 0 / # of axes in frame EXTEND = T / Extension may be present ORIGIN = 'ESO ' / European Southern Observatory DATE = '2006-03-21T15:06:48' / Date this file was written TELESCOP= 'VISTA ' / ESO Telescope Name INSTRUME= 'VIRCAM ' / Instrument used. OBJECT = 'OBJECT ' / Original target. RA = 318.346792 / 21:13:23.2 RA (J2000) pointing (deg) DEC = -88.93761 / -88:56:15.3 DEC (J2000) pointing (deg) EQUINOX = 2000. / Standard FK5 (years) RADECSYS= 'FK5 ' / Coordinate reference frame EXPTIME = 10.0000000 / Integration time MJD-OBS = 53815.62973579 / Obs start DATE-OBS= '2006-03-21T15:06:49.1726' / Observing date UTC = 54270.829 / 15:04:30.829 UTC at start (sec) LST = 80333.420 / 22:18:53.420 LST at start (sec) PI-COI = 'J.Lewis-P.Bunclark' / PI-COI name. OBSERVER= 'Peter Bunclark' / Name of observer. ORIGFILE= 'VIRCAM_IMG_OBS080_0001.fits' / Original File Name COMMENT VISTA IR Camera OS $Revision: 0.21 $ HIERARCH ESO ADA ABSROT END = 0.00000 / Abs rot angle at exp end (deg) HIERARCH ESO DPR CATG = 'TEST ' / Observation category HIERARCH ESO DPR TECH = 'IMAGE,FILTOFFSET' / Observation technique HIERARCH ESO DPR TYPE = 'STD,STRAYLIGHT' / Observation type HIERARCH ESO INS DATE = '2005-12-14' / Instrument release date (yyyy-mm-d HIERARCH ESO INS FILT1 DATE = '2006-01-27T10:02:27' / Filter index time HIERARCH ESO INS FILT1 FOCUS = 0.000 / Filter focus offset [mm] HIERARCH ESO INS FILT1 ID = 'SLOT8 ' / Filter unique id HIERARCH ESO INS FILT1 NAME = 'Y ' / Filter name HIERARCH ESO INS FILT1 NO = 25 / Filter wheel position index HIERARCH ESO INS FILT1 WLEN = 0.000 / Filter effective wavelength [nm] HIERARCH ESO INS HB1 SWSIM = F / If T, heart beat device simulated HIERARCH ESO INS ID = 'VIRCAM/1.56' / Instrument ID HIERARCH ESO INS LSC1 OK = T / If T, controller is operational HIERARCH ESO INS LSC1 SWSIM = F / If T, lakeshore ctrllr simulated HIERARCH ESO INS LSM1 OK = T / If T, controller is operational HIERARCH ESO INS LSM1 SWSIM = F / If T, lakeshore monitor simulated HIERARCH ESO INS LSM2 OK = T / If T, controller is operational HIERARCH ESO INS LSM2 SWSIM = F / If T, lakeshore monitor simulated HIERARCH ESO INS LSM3 OK = T / If T, controller is operational HIERARCH ESO INS LSM3 SWSIM = F / If T, lakeshore monitor simulated HIERARCH ESO INS PRES1 ID = 'Vac1 ' / Pressure sensor type HIERARCH ESO INS PRES1 NAME = 'Vacuum gauge 1' / Pressure sensor name HIERARCH ESO INS PRES1 UNIT = 'mbar ' / Pressure unit HIERARCH ESO INS PRES1 VAL = 0.000 / Pressure [mbar] HIERARCH ESO INS SW1 ID = 'INPOS ' / Switch ID HIERARCH ESO INS SW1 NAME = 'Filter In-position Switch' / Switch name HIERARCH ESO INS SW1 STATUS = 'INACTIVE' / Switch status HIERARCH ESO INS SW2 ID = 'REFSW ' / Switch ID HIERARCH ESO INS SW2 NAME = 'Filter Reference Select' / Switch name HIERARCH ESO INS SW2 STATUS = 'PRIMARY ' / Switch status HIERARCH ESO INS SW3 ID = 'HOME ' / Switch ID HIERARCH ESO INS SW3 NAME = 'Filter Reference Switch' / Switch name HIERARCH ESO INS SW3 STATUS = 'INACTIVE' / Switch status HIERARCH ESO INS TEMP1 ID = 'Amb ' / Temperature sensor type


VISTA Data Flow System
HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS

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TEMP1 TEMP1 TEMP1 TEMP10 TEMP10 TEMP10 TEMP10 TEMP12 TEMP12 TEMP12 TEMP12 TEMP14 TEMP14 TEMP14 TEMP14 TEMP15 TEMP15 TEMP15 TEMP15 TEMP16 TEMP16 TEMP16 TEMP16 TEMP17 TEMP17 TEMP17 TEMP17 TEMP18 TEMP18 TEMP18 TEMP18 TEMP19 TEMP19 TEMP19 TEMP19 TEMP2 TEMP2 TEMP2 TEMP2 TEMP20 TEMP20 TEMP20 TEMP20 TEMP21 TEMP21 TEMP21 TEMP21 TEMP22 TEMP22 TEMP22 TEMP22 TEMP23 TEMP23 TEMP23 TEMP23 TEMP24 TEMP24 TEMP24 TEMP24 TEMP25 TEMP25 TEMP25 TEMP25 TEMP26 TEMP26 TEMP26 TEMP26 TEMP3 TEMP3 TEMP3 TEMP3 TEMP4 TEMP4

NAME UNIT VAL ID NAME UNIT VAL ID NAME UNIT VAL ID NAME UNIT VAL ID NAME UNIT VAL ID NAME UNIT VAL ID NAME UNIT VAL ID NAME UNIT VAL ID NAME UNIT VAL ID NAME UNIT VAL ID NAME UNIT VAL ID NAME UNIT VAL ID NAME UNIT VAL ID NAME UNIT VAL ID NAME UNIT VAL ID NAME UNIT VAL ID NAME UNIT VAL ID NAME UNIT VAL ID NAME

= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =

'Ambient temperature' / Temperature sensor name 'K ' / Temperature unit 302.580 / Temperature [K] 'CC1_2 ' / Temperature sensor type 'Cryo cooler 1 2nd' / Temperature sensor name 'K ' / Temperature unit 24.105 / Temperature [K] 'CC2_2 ' / Temperature sensor type 'Cryo cooler 2 2nd' / Temperature sensor name 'K ' / Temperature unit 27.791 / Temperature [K] 'CC3_2 ' / Temperature sensor type 'Cryo cooler 3 2nd' / Temperature sensor name 'K ' / Temperature unit 22.735 / Temperature [K] 'WFSN ' / Temperature sensor type 'WFS CCD assembly PY' / Temperature sensor name 'K ' / Temperature unit 1.000 / Temperature [K] 'WFSS ' / Temperature sensor type 'WFS CCD assembly NY' / Temperature sensor name 'K ' / Temperature unit 123.550 / Temperature [K] 'Dt1AB ' / Temperature sensor type 'Science detector 1AB' / Temperature sensor name 'K ' / Temperature unit 73.583 / Temperature [K] 'Dt1CD ' / Temperature sensor type 'Science detector 1CD' / Temperature sensor name 'K ' / Temperature unit 73.002 / Temperature [K] 'Dt2BA ' / Temperature sensor type 'Science detector 2BA' / Temperature sensor name 'K ' / Temperature unit 74.668 / Temperature [K] 'Win ' / Temperature sensor type 'Cryostat window cell' / Temperature sensor name 'K ' / Temperature unit 176.710 / Temperature [K] 'Dt2DC ' / Temperature sensor type 'Science detector 2DC' / Temperature sensor name 'K ' / Temperature unit 74.106 / Temperature [K] 'Dt3AB ' / Temperature sensor type 'Science detector 3AB' / Temperature sensor name 'K ' / Temperature unit 74.677 / Temperature [K] 'Dt3CD ' / Temperature sensor type 'Science detector 3CD' / Temperature sensor name 'K ' / Temperature unit 75.485 / Temperature [K] 'Dt4BA ' / Temperature sensor type 'Science detector 4BA' / Temperature sensor name 'K ' / Temperature unit 74.778 / Temperature [K] 'Dt4DC ' / Temperature sensor type 'Science detector 4DC' / Temperature sensor name 'K ' / Temperature unit 74.544 / Temperature [K] 'FPA ' / Temperature sensor type 'FPA thermal plate' / Temperature sensor name 'K ' / Temperature unit 69.997 / Temperature [K] 'WFSpl ' / Temperature sensor type 'WFS plate' / Temperature sensor name 'K ' / Temperature unit 108.360 / Temperature [K] 'Tube ' / Temperature sensor type 'Cryostat tube' / Temperature sensor name 'K ' / Temperature unit 33.256 / Temperature [K] 'LNtnk ' / Temperature sensor type 'Liquid nitrogen tank' / Temperature sensor name


VISTA Data Flow System
HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS INS OBS OBS OBS OBS OBS OBS OBS OBS OBS OCS OCS OCS TEL TEL TEL TEL TEL TEL TEL TEL TEL TEL TEL TEL TEL TEL TEL TEL TEL TEL TEL TEL TEL TEL TEL TEL TEL TEL TEL TEL TEL TEL TEL TEL TEL TEL TEL TEL TEL TEL

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TEMP4 UNIT = 'K ' / Temperature unit TEMP4 VAL = 103.180 / Temperature [K] TEMP5 ID = 'Baff ' / Temperature sensor type TEMP5 NAME = 'Baffle ' / Temperature sensor name TEMP5 UNIT = 'K ' / Temperature unit TEMP5 VAL = 21.332 / Temperature [K] TEMP6 ID = 'Lens ' / Temperature sensor type TEMP6 NAME = 'Lens barrel' / Temperature sensor name TEMP6 UNIT = 'K ' / Temperature unit TEMP6 VAL = 100.570 / Temperature [K] TEMP7 ID = 'FwShd ' / Temperature sensor type TEMP7 NAME = 'Filter wheel shield' / Temperature sensor name TEMP7 UNIT = 'K ' / Temperature unit TEMP7 VAL = 124.420 / Temperature [K] TEMP8 ID = 'FwHub ' / Temperature sensor type TEMP8 NAME = 'Filter wheel hub' / Temperature sensor name TEMP8 UNIT = 'K ' / Temperature unit TEMP8 VAL = 109.570 / Temperature [K] THERMAL DET MEAN= 0.00 / Detector mean temperature [K] THERMAL DET TARGET= 70.00 / Detector target temperature [K] THERMAL ENABLE= F / If T, enable thermal control VAC1 OK = T / If T, controller is operational VAC1 SWSIM = F / If T, vacuum sensor simulated DID = 'ESO-VLT-DIC.OBS-1.11' / OBS Dictionary GRP = '0 ' / linked blocks ID = -1 / Observation block ID NAME = 'Maintenance' / OB name PI-COI ID = 0 / ESO internal PI-COI ID PI-COI NAME = 'M.Caldwell-A.Born' / PI-COI name PROG ID = 'Maintenance' / ESO program identification START = '2006-01-30T13:54:10' / OB start time TPLNO = 1 / Template number within OB DET1 IMGNAME= 'VIRCAM_GEN_STD' / Data File Name. RECIPE = 'DEFAULT ' / Data reduction recipe to be used REQTIME = 10.000 / Requested integration time [s] ABSROT START= 0.000 / Abs rotator angle at start AIRM END = 0.000 / Airmass at end AIRM START = 0.000 / Airmass at start ALT = 25.691 / Alt angle at start (deg) AMBI FWHM END= -1.00 / Observatory Seeing queried from AS AMBI FWHM START= -1.00 / Observatory Seeing queried from AS AMBI PRES END= 750.00 / Observatory ambient air pressure q AMBI PRES START= 750.00 / Observatory ambient air pressure q AMBI RHUM = 12. / Observatory ambient relative humi AMBI TAU0 = 0.000000 / Average coherence time AMBI TEMP = 10.00 / Observatory ambient temperature qu AMBI WINDDIR= 0. / Observatory ambient wind directio AMBI WINDSP = 10.00 / Observatory ambient wind speed que AO ALT = 0.000000 / Altitude of last closed loop aO AO DATE =' ' / Last closed loop aO AO M1 DATE = '2006-03-21T15:06:47' / Last M1 update AO M2 DATE = '2006-03-21T15:06:46' / Last M2 update AO MODES = 0 / Which aO modes corrected closed lo AZ = 0.317 / Az angle at start (deg) S=0,W=90 DATE = 'not set ' / TCS installation date DID = 'ESO-VLT-DIC.TCS-01.00' / Data dictionary for TEL DID1 = 'ESO-VLT-DIC.VTCS-0.2' / Additional data dict. fo DOME STATUS = 'FULLY-OPEN' / Dome status ECS FLATFIELD= 0 / Flat field level ECS MOONSCR = 0.00 / Moon screen position ECS VENT1 = 0.00 / State of vent i ECS VENT2 = 0.00 / State of vent i ECS VENT3 = 0.00 / State of vent i ECS WINDSCR = 0.00 / Wind screen position FOCU ID = 'CA ' / Telescope focus station ID FOCU VALUE = 0.000 / M2 setting (mm) GEOELEV = 2530. / Elevation above sea level (m) GEOLAT = -24.6157 / Tel geo latitute (+=North) (deg) GEOLON = -70.3976 / Tel geo longitude (+=East) (deg) GUID FWHM = 0.00 / Seeing measured by autoguider GUID STATUS = 'OFF ' / Status of autoguider ID = 'v 0.44 ' / TCS version number M2 ACENTRE = 0.00 / M2 centring alpha


VISTA Data Flow System
HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH NJITTER = NOFFSETS= NUSTEP = OBSNUM = REQTIME = END XTENSION= BITPIX = NAXIS = NAXIS1 = NAXIS2 = PCOUNT = GCOUNT = EXTNAME = EXTVER = ORIGIN = DATE = EXPTIME = MJD-OBS = DATE-OBS= CTYPE1 = CTYPE2 = CRVAL1 = CRVAL2 = CRPIX1 = CRPIX2 = CDELT1 = CDELT2 = CD1_1 = CD1_2 = CD2_1 = CD2_2 = HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO TEL TEL TEL TEL TEL TEL TEL TEL TEL TEL TEL TEL TEL TEL TEL TEL TEL TEL TEL TEL TEL TEL TEL TPL TPL TPL TPL TPL TPL TPL TPL

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M2 ATILT = 0.00 / M2 tilt alpha M2 BCENTRE = 0.00 / M2 centring beta M2 BTILT = 0.00 / M2 tilt beta M2 Z = 0.00000 / Focussing position of M2 in Z coor MOON DEC = -27.46744 / -27:28:02.7 DEC (J2000) (deg) MOON RA = 253.667459 / 16:54:40.1 RA (J2000) (deg) OPER = 'Operator name not set' / Telescope Operator PARANG END = 0.000 / Parallactic angle at end (deg) PARANG START= 0.000 / Parallactic angle at start (deg) POSANG = 0.000 / Rot position angle at start TARG ALPHA = 211323.230 / Alpha coordinate for the target TARG COORDTYPE= 'M ' / Coordinate type (M=mean A=apparent TARG DELTA = -885615.400 / Delta coordinate for the target TARG EPOCH = 2000.000 / Epoch TARG EPOCHSYSTEM= 'J ' / Epoch system (default J=Julian) TARG EQUINOX= 2000.000 / Equinox TARG PARALLAX= 0.000 / Parallax TARG PMA = 0.000000 / Proper Motion Alpha TARG PMD = 0.000000 / Proper motion Delta TARG RADVEL = 0.000 / Radial velocity TH M1 TEMP = 0.00 / M1 superficial temperature TH STR TEMP = 0.00 / Telescope structure temperature TRAK STATUS = 'NORMAL ' / Tracking status DID = 'ESO-VLT-DIC.TPL-1.9' / Data dictionary for TPL EXPNO = 1 / Exposure number within template ID = 'VIRCAM_gen_tec_StrayLight' / Template signature NAME = 'VIRCAM stray light investigation' / Template nam NEXP = 6 / Number of exposures within templat PRESEQ = 'VIRCAM_gen_tec_StrayLight.seq' / Sequencer scrip START = '2006-01-30T13:54:10' / TPL start time VERSION = '$Revision: 0.13 $' / Version of the template 0 / Number of jitter positions 0 / Number of offset positions 0 / Number of microstep positions 1 / Observation number 10.000 / Requested integration time [s] ' 32 2 2048 2048 0 1 / / / / / / / / IMAGE extension # of bits per pix value # of axes in data array # of pixels in axis1 # of pixels in axis2 number of random group parameters number of random groups Extension name

'IMAGE

'DET1.CHIP9' 1 / Extension version 'ESO ' / European Southern Observatory '2006-01-30T13:54:47.7333' / Date the file was written 10.0000000 / Integration time 53765.57956362 / Obs start 2006-01-30T13:54:34.297 '2006-01-30T13:54:34.2967' / Observing date 'RA---ZPN' / Coord type of celestial axis 1 'DEC--ZPN' / Coord type of celestial axis 2 318.346791667 / RA at reference pixel -88.9376111111 / Dec at reference pixel 5401.6 / Pixel coordinate at ref point 6860.8 / Pixel coordinate at ref point 9.49444444444444E-05 / Coordinate increment -9.49444444444444E-05 / Coordinate increment 5.81347849634012E-21 / WCS transform matrix element 9.49444444444444E-05 / WCS transform matrix element -9.49444444444444E-05 / WCS transform matrix element -5.81347849634012E-21 / WCS transform matrix element ESO DET CHIP ID = 'ESO-Virgo45' / Detector ID ESO DET CHIP LIVE = T / Detector live or broken ESO DET CHIP NAME = 'Virgo' / Detector name ESO DET CHIP NO = 9 / Unique Detector Number ESO DET CHIP NX = 2048 / Pixels in X ESO DET CHIP NY = 2048 / Pixels in Y ESO DET CHIP PXSPACE= 2.000e-05 / Pixel-Pixel Spacing ESO DET CHIP TYPE = 'IR' / The Type of Det Chip ESO DET CHIP VIGNETD = F / Detector chip vignetted?


VISTA Data Flow System
HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET

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CHIP X CHIP Y CHOP FREQ CON OPMODE DID DIT DITDELAY EXP NAME EXP NO EXP UTC FRAM NO FRAM TYPE FRAM UTC IRACE ADC1 IRACE ADC1 IRACE ADC1 IRACE ADC1 IRACE ADC1 IRACE ADC1 IRACE ADC10 IRACE ADC10 IRACE ADC10 IRACE ADC10 IRACE ADC10 IRACE ADC10 IRACE ADC11 IRACE ADC11 IRACE ADC11 IRACE ADC11 IRACE ADC11 IRACE ADC11 IRACE ADC12 IRACE ADC12 IRACE ADC12 IRACE ADC12 IRACE ADC12 IRACE ADC12 IRACE ADC13 IRACE ADC13 IRACE ADC13 IRACE ADC13 IRACE ADC13 IRACE ADC13 IRACE ADC14 IRACE ADC14 IRACE ADC14 IRACE ADC14 IRACE ADC14 IRACE ADC14 IRACE ADC15 IRACE ADC15 IRACE ADC15 IRACE ADC15 IRACE ADC15 IRACE ADC15 IRACE ADC16 IRACE ADC16 IRACE ADC16 IRACE ADC16 IRACE ADC16 IRACE ADC16 IRACE ADC2 IRACE ADC2 IRACE ADC2 IRACE ADC2 IRACE ADC2 IRACE ADC2 IRACE ADC3 IRACE ADC3 IRACE ADC3 IRACE ADC3 IRACE ADC3 IRACE ADC3

= 3 / Detector position x-axis = 4 / Detector position y-axis = 0 / Chopping Frequency = 'NORMAL' / Operational Mode = 'ESO-VLT-DIC.IRACE-1.34' / Dictionary Name and Re = 10.0000000 / Integration Time = 0.000 / Pause Between DITs = 'VIRCAM_GEN_STD030_0001' / Exposure Name = 3 / Exposure number = '2006-01-30T13:54:47.7333' / File Creation Time = 1 / Frame number = 'INT' / Frame type = '2006-01-30T13:54:46.7037' / Time Recv Frame DELAY= 7 / ADC Delay Adjustment ENABLE= 1 / Enable ADC Board (0/1) FILTER1= 0 / ADC Filter1 Adjustment FILTER2= 0 / ADC Filter2 Adjustment HEADER= 1 / Header of ADC Board NAME= 'VISTA-AQ-GRP' / Name for ADC Board DELAY= 7 / ADC Delay Adjustment ENABLE= 1 / Enable ADC Board (0/1) FILTER1= 0 / ADC Filter1 Adjustment FILTER2= 0 / ADC Filter2 Adjustment HEADER= 1 / Header of ADC Board NAME= 'VISTA-AQ-GRP' / Name for ADC Board DELAY= 7 / ADC Delay Adjustment ENABLE= 1 / Enable ADC Board (0/1) FILTER1= 0 / ADC Filter1 Adjustment FILTER2= 0 / ADC Filter2 Adjustment HEADER= 1 / Header of ADC Board NAME= 'VISTA-AQ-GRP' / Name for ADC Board DELAY= 7 / ADC Delay Adjustment ENABLE= 1 / Enable ADC Board (0/1) FILTER1= 0 / ADC Filter1 Adjustment FILTER2= 0 / ADC Filter2 Adjustment HEADER= 1 / Header of ADC Board NAME= 'VISTA-AQ-GRP' / Name for ADC Board DELAY= 7 / ADC Delay Adjustment ENABLE= 1 / Enable ADC Board (0/1) FILTER1= 0 / ADC Filter1 Adjustment FILTER2= 0 / ADC Filter2 Adjustment HEADER= 1 / Header of ADC Board NAME= 'VISTA-AQ-GRP' / Name for ADC Board DELAY= 7 / ADC Delay Adjustment ENABLE= 1 / Enable ADC Board (0/1) FILTER1= 0 / ADC Filter1 Adjustment FILTER2= 0 / ADC Filter2 Adjustment HEADER= 1 / Header of ADC Board NAME= 'VISTA-AQ-GRP' / Name for ADC Board DELAY= 7 / ADC Delay Adjustment ENABLE= 1 / Enable ADC Board (0/1) FILTER1= 0 / ADC Filter1 Adjustment FILTER2= 0 / ADC Filter2 Adjustment HEADER= 1 / Header of ADC Board NAME= 'VISTA-AQ-GRP' / Name for ADC Board DELAY= 7 / ADC Delay Adjustment ENABLE= 1 / Enable ADC Board (0/1) FILTER1= 0 / ADC Filter1 Adjustment FILTER2= 0 / ADC Filter2 Adjustment HEADER= 1 / Header of ADC Board NAME= 'VISTA-AQ-GRP' / Name for ADC Board DELAY= 7 / ADC Delay Adjustment ENABLE= 1 / Enable ADC Board (0/1) FILTER1= 0 / ADC Filter1 Adjustment FILTER2= 0 / ADC Filter2 Adjustment HEADER= 1 / Header of ADC Board NAME= 'VISTA-AQ-GRP' / Name for ADC Board DELAY= 7 / ADC Delay Adjustment ENABLE= 1 / Enable ADC Board (0/1) FILTER1= 0 / ADC Filter1 Adjustment FILTER2= 0 / ADC Filter2 Adjustment HEADER= 1 / Header of ADC Board NAME= 'VISTA-AQ-GRP' / Name for ADC Board


VISTA Data Flow System
HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET

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IRACE ADC4 DELAY= 7 / ADC Delay Adjustment IRACE ADC4 ENABLE= 1 / Enable ADC Board (0/1) IRACE ADC4 FILTER1= 0 / ADC Filter1 Adjustment IRACE ADC4 FILTER2= 0 / ADC Filter2 Adjustment IRACE ADC4 HEADER= 1 / Header of ADC Board IRACE ADC4 NAME= 'VISTA-AQ-GRP' / Name for ADC Board IRACE ADC5 DELAY= 7 / ADC Delay Adjustment IRACE ADC5 ENABLE= 1 / Enable ADC Board (0/1) IRACE ADC5 FILTER1= 0 / ADC Filter1 Adjustment IRACE ADC5 FILTER2= 0 / ADC Filter2 Adjustment IRACE ADC5 HEADER= 1 / Header of ADC Board IRACE ADC5 NAME= 'VISTA-AQ-GRP' / Name for ADC Board IRACE ADC6 DELAY= 7 / ADC Delay Adjustment IRACE ADC6 ENABLE= 1 / Enable ADC Board (0/1) IRACE ADC6 FILTER1= 0 / ADC Filter1 Adjustment IRACE ADC6 FILTER2= 0 / ADC Filter2 Adjustment IRACE ADC6 HEADER= 1 / Header of ADC Board IRACE ADC6 NAME= 'VISTA-AQ-GRP' / Name for ADC Board IRACE ADC7 DELAY= 7 / ADC Delay Adjustment IRACE ADC7 ENABLE= 1 / Enable ADC Board (0/1) IRACE ADC7 FILTER1= 0 / ADC Filter1 Adjustment IRACE ADC7 FILTER2= 0 / ADC Filter2 Adjustment IRACE ADC7 HEADER= 1 / Header of ADC Board IRACE ADC7 NAME= 'VISTA-AQ-GRP' / Name for ADC Board IRACE ADC8 DELAY= 7 / ADC Delay Adjustment IRACE ADC8 ENABLE= 1 / Enable ADC Board (0/1) IRACE ADC8 FILTER1= 0 / ADC Filter1 Adjustment IRACE ADC8 FILTER2= 0 / ADC Filter2 Adjustment IRACE ADC8 HEADER= 1 / Header of ADC Board IRACE ADC8 NAME= 'VISTA-AQ-GRP' / Name for ADC Board IRACE ADC9 DELAY= 7 / ADC Delay Adjustment IRACE ADC9 ENABLE= 1 / Enable ADC Board (0/1) IRACE ADC9 FILTER1= 0 / ADC Filter1 Adjustment IRACE ADC9 FILTER2= 0 / ADC Filter2 Adjustment IRACE ADC9 HEADER= 1 / Header of ADC Board IRACE ADC9 NAME= 'VISTA-AQ-GRP' / Name for ADC Board IRACE SEQCONT= 'F' / Sequencer Continuous Mode MINDIT = 1.0011000 / Minimum DIT MODE NAME = '' / DCS Detector Mode NCORRS = 2 / Read-Out Mode NCORRS NAME = 'Double' / Read-Out Mode Name NDIT = 1 / # of Sub-Integrations NDITSKIP = 0 / DITs skipped at 1st.INT RSPEED = 1 / Read-Speed Factor RSPEEDADD = 0 / Read-Speed Add VOLT1 CLKHI1= 4.0000 / Set Value High-Clock VOLT1 CLKHI10= 4.0000 / Set Value High-Clock VOLT1 CLKHI11= 4.0000 / Set Value High-Clock VOLT1 CLKHI12= 5.0000 / Set Value High-Clock VOLT1 CLKHI13= 1.0000 / Set Value High-Clock VOLT1 CLKHI14= 4.0000 / Set Value High-Clock VOLT1 CLKHI15= 0.0000 / Set Value High-Clock VOLT1 CLKHI16= 2.5000 / Set Value High-Clock VOLT1 CLKHI2= 4.0000 / Set Value High-Clock VOLT1 CLKHI3= 4.0000 / Set Value High-Clock VOLT1 CLKHI4= 5.0000 / Set Value High-Clock VOLT1 CLKHI5= 1.0000 / Set Value High-Clock VOLT1 CLKHI6= 4.0000 / Set Value High-Clock VOLT1 CLKHI7= 0.0000 / Set Value High-Clock VOLT1 CLKHI8= 2.5000 / Set Value High-Clock VOLT1 CLKHI9= 4.0000 / Set Value High-Clock VOLT1 CLKHINM1= 'clk1Hi pmc' / Name of High-Clock VOLT1 CLKHINM10= 'clk10Hi FrameStart' / Name of High-Clock VOLT1 CLKHINM11= 'clk11Hi UcResetEnable' / Name of High-Clock VOLT1 CLKHINM12= 'clk12Hi VHiRowEnable' / Name of High-Clock VOLT1 CLKHINM13= 'clk13Hi VLoRowEnable' / Name of High-Clock VOLT1 CLKHINM14= 'clk14Hi VHiReset' / Name of High-Clock VOLT1 CLKHINM15= 'clk15Hi VLoReset' / Name of High-Clock VOLT1 CLKHINM16= 'clk16Hi VpOut' / Name of High-Clock VOLT1 CLKHINM2= 'clk2Hi FrameStart' / Name of High-Clock VOLT1 CLKHINM3= 'clk3Hi UcResetEnable' / Name of High-Clock VOLT1 CLKHINM4= 'clk4Hi VHiRowEnable' / Name of High-Clock VOLT1 CLKHINM5= 'clk5Hi VLoRowEnable' / Name of High-Clock


VISTA Data Flow System
HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1

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CLKHINM6= 'clk6Hi VHiReset' / Name of High-Clock CLKHINM7= 'clk7Hi VLoReset' / Name of High-Clock CLKHINM8= 'clk8Hi VpOut' / Name of High-Clock CLKHINM9= 'clk9Hi pmc' / Name of High-Clock CLKHIT1= 4.0283 / Tel Value High-Clock CLKHIT10= 4.0234 / Tel Value High-Clock CLKHIT11= 4.0234 / Tel Value High-Clock CLKHIT12= 5.0244 / Tel Value High-Clock CLKHIT13= 1.0352 / Tel Value High-Clock CLKHIT14= 4.0283 / Tel Value High-Clock CLKHIT15= 0.0439 / Tel Value High-Clock CLKHIT16= 2.5293 / Tel Value High-Clock CLKHIT2= 4.0283 / Tel Value High-Clock CLKHIT3= 4.0283 / Tel Value High-Clock CLKHIT4= 5.0195 / Tel Value High-Clock CLKHIT5= 1.0352 / Tel Value High-Clock CLKHIT6= 4.0332 / Tel Value High-Clock CLKHIT7= 0.0439 / Tel Value High-Clock CLKHIT8= 2.5293 / Tel Value High-Clock CLKHIT9= 4.0430 / Tel Value High-Clock CLKLO1= 0.0000 / Set value Low-Clock CLKLO10= 0.0000 / Set value Low-Clock CLKLO11= 0.0000 / Set value Low-Clock CLKLO12= 5.0000 / Set value Low-Clock CLKLO13= 1.0000 / Set value Low-Clock CLKLO14= 4.0000 / Set value Low-Clock CLKLO15= 0.0000 / Set value Low-Clock CLKLO16= 9.7500 / Set value Low-Clock CLKLO2= 0.0000 / Set value Low-Clock CLKLO3= 0.0000 / Set value Low-Clock CLKLO4= 5.0000 / Set value Low-Clock CLKLO5= 1.0000 / Set value Low-Clock CLKLO6= 4.0000 / Set value Low-Clock CLKLO7= 0.0000 / Set value Low-Clock CLKLO8= 9.7500 / Set value Low-Clock CLKLO9= 0.0000 / Set value Low-Clock CLKLONM1= 'clk1Lo pmc' / Name of Low-Clock CLKLONM10= 'clk10Lo FrameStart' / Name of Low-Clock CLKLONM11= 'clk11Lo UcResetEnable' / Name of Low-Clock CLKLONM12= 'clk12Lo VHiRowEnable' / Name of Low-Clock CLKLONM13= 'clk13Lo VLoRowEnable' / Name of Low-Clock CLKLONM14= 'clk14Lo VHiReset' / Name of Low-Clock CLKLONM15= 'clk15Lo VLoReset' / Name of Low-Clock CLKLONM16= 'clk16Lo VpOut' / Name of Low-Clock CLKLONM2= 'clk2Lo FrameStart' / Name of Low-Clock CLKLONM3= 'clk3Lo UcResetEnable' / Name of Low-Clock CLKLONM4= 'clk4Lo VHiRowEnable' / Name of Low-Clock CLKLONM5= 'clk5Lo VLoRowEnable' / Name of Low-Clock CLKLONM6= 'clk6Lo VHiReset' / Name of Low-Clock CLKLONM7= 'clk7Lo VLoReset' / Name of Low-Clock CLKLONM8= 'clk8Lo VpOut' / Name of Low-Clock CLKLONM9= 'clk9Lo pmc' / Name of Low-Clock CLKLOT1= 0.0391 / Tel Value Low-Clock CLKLOT10= 0.0391 / Tel Value Low-Clock CLKLOT11= 0.0439 / Tel Value Low-Clock CLKLOT12= 4.9609 / Tel Value Low-Clock CLKLOT13= 1.0254 / Tel Value Low-Clock CLKLOT14= 4.0283 / Tel Value Low-Clock CLKLOT15= 0.0342 / Tel Value Low-Clock CLKLOT16= 9.4824 / Tel Value Low-Clock CLKLOT2= 0.0391 / Tel Value Low-Clock CLKLOT3= 0.0293 / Tel Value Low-Clock CLKLOT4= 4.9609 / Tel Value Low-Clock CLKLOT5= 1.0303 / Tel Value Low-Clock CLKLOT6= 4.0234 / Tel Value Low-Clock CLKLOT7= 0.0342 / Tel Value Low-Clock CLKLOT8= 9.4775 / Tel Value Low-Clock CLKLOT9= 0.0439 / Tel Value Low-Clock DC1 = -2.3600 / Set value DC-Voltage DC10 = -3.3500 / Set value DC-Voltage DC11 = 0.0000 / Set value DC-Voltage DC12 = 0.7000 / Set value DC-Voltage DC13 = 0.7000 / Set value DC-Voltage


VISTA Data Flow System
HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT1 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2

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DC14 = DC15 = DC16 = DC2 = DC3 = DC4 = DC5 = DC6 = DC7 = DC8 = DC9 = DCNM1 = DCNM10= DCNM11= DCNM12= DCNM13= DCNM14= DCNM15= DCNM16= DCNM2 = DCNM3 = DCNM4 = DCNM5 = DCNM6 = DCNM7 = DCNM8 = DCNM9 = DCTA1 = DCTA10= DCTA11= DCTA12= DCTA13= DCTA14= DCTA15= DCTA16= DCTA2 = DCTA3 = DCTA4 = DCTA5 = DCTA6 = DCTA7 = DCTA8 = DCTA9 = DCTB1 = DCTB10= DCTB11= DCTB12= DCTB13= DCTB14= DCTB15= DCTB16= DCTB2 = DCTB3 = DCTB4 = DCTB5 = DCTB6 = DCTB7 = DCTB8 = DCTB9 = CLKHI1= CLKHI10= CLKHI11= CLKHI12= CLKHI13= CLKHI14= CLKHI15= CLKHI16= CLKHI2= CLKHI3= CLKHI4= CLKHI5= CLKHI6= CLKHI7=

3.5000 / Set value DC-Voltage 2.2000 / Set value DC-Voltage 3.3000 / Set value DC-Voltage -3.3500 / Set value DC-Voltage 0.0000 / Set value DC-Voltage 0.7000 / Set value DC-Voltage 0.7000 / Set value DC-Voltage 3.5000 / Set value DC-Voltage 2.2000 / Set value DC-Voltage 3.3000 / Set value DC-Voltage -2.3600 / Set value DC-Voltage 'DC1 VIdle' / Name of DC-voltage 'DC10 VSlew' / Name of DC-voltage 'DC11 VRstUc' / Name of DC-voltage 'DC12 VDetCom' / Name of DC-voltage 'DC13 VnUc' / Name of DC-voltage 'DC14 VpUc' / Name of DC-voltage 'DC15 VnOut' / Name of DC-voltage 'DC16 RefBias' / Name of DC-voltage 'DC2 VSlew' / Name of DC-voltage 'DC3 VRstUc' / Name of DC-voltage 'DC4 VDetCom' / Name of DC-voltage 'DC5 VnUc' / Name of DC-voltage 'DC6 VpUc' / Name of DC-voltage 'DC7 VnOut' / Name of DC-voltage 'DC8 RefBias' / Name of DC-voltage 'DC9 VIdle' / Name of DC-voltage -2.3633 / Tel Value 1 for DC -3.3594 / Tel Value 1 for DC 0.0000 / Tel Value 1 for DC 0.7031 / Tel Value 1 for DC 0.7031 / Tel Value 1 for DC 3.5010 / Tel Value 1 for DC 2.1973 / Tel Value 1 for DC 3.3008 / Tel Value 1 for DC -3.3545 / Tel Value 1 for DC 0.0049 / Tel Value 1 for DC 0.6982 / Tel Value 1 for DC 0.6982 / Tel Value 1 for DC 3.5010 / Tel Value 1 for DC 2.1973 / Tel Value 1 for DC 3.2959 / Tel Value 1 for DC -2.3682 / Tel Value 1 for DC -2.3535 / Tel Value 2 for DC -3.3203 / Tel Value 2 for DC 0.0000 / Tel Value 2 for DC 0.6982 / Tel Value 2 for DC 0.7031 / Tel Value 2 for DC 3.5010 / Tel Value 2 for DC 2.1826 / Tel Value 2 for DC 3.2959 / Tel Value 2 for DC -3.3154 / Tel Value 2 for DC 0.0000 / Tel Value 2 for DC 0.6982 / Tel Value 2 for DC 0.6982 / Tel Value 2 for DC 3.4961 / Tel Value 2 for DC 2.1826 / Tel Value 2 for DC 3.2959 / Tel Value 2 for DC -2.3584 / Tel Value 2 for DC 4.0000 / Set Value High-Clock 4.0000 / Set Value High-Clock 4.0000 / Set Value High-Clock 5.0000 / Set Value High-Clock 1.0000 / Set Value High-Clock 4.0000 / Set Value High-Clock 0.0000 / Set Value High-Clock 2.5000 / Set Value High-Clock 4.0000 / Set Value High-Clock 4.0000 / Set Value High-Clock 5.0000 / Set Value High-Clock 1.0000 / Set Value High-Clock 4.0000 / Set Value High-Clock 0.0000 / Set Value High-Clock


VISTA Data Flow System
HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2

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CLKHI8= 2.5000 / Set Value High-Clock CLKHI9= 4.0000 / Set Value High-Clock CLKHINM1= 'clk1Hi pmc' / Name of High-Clock CLKHINM10= 'clk10Hi FrameStart' / Name of High-Clock CLKHINM11= 'clk11Hi UcResetEnable' / Name of High-Clock CLKHINM12= 'clk12Hi VHiRowEnable' / Name of High-Clock CLKHINM13= 'clk13Hi VLoRowEnable' / Name of High-Clock CLKHINM14= 'clk14Hi VHiReset' / Name of High-Clock CLKHINM15= 'clk15Hi VLoReset' / Name of High-Clock CLKHINM16= 'clk16Hi VpOut' / Name of High-Clock CLKHINM2= 'clk2Hi FrameStart' / Name of High-Clock CLKHINM3= 'clk3Hi UcResetEnable' / Name of High-Clock CLKHINM4= 'clk4Hi VHiRowEnable' / Name of High-Clock CLKHINM5= 'clk5Hi VLoRowEnable' / Name of High-Clock CLKHINM6= 'clk6Hi VHiReset' / Name of High-Clock CLKHINM7= 'clk7Hi VLoReset' / Name of High-Clock CLKHINM8= 'clk8Hi VpOut' / Name of High-Clock CLKHINM9= 'clk9Hi pmc' / Name of High-Clock CLKHIT1= 4.0283 / Tel Value High-Clock CLKHIT10= 4.0234 / Tel Value High-Clock CLKHIT11= 4.0186 / Tel Value High-Clock CLKHIT12= 5.0098 / Tel Value High-Clock CLKHIT13= 1.0400 / Tel Value High-Clock CLKHIT14= 4.0283 / Tel Value High-Clock CLKHIT15= 0.0488 / Tel Value High-Clock CLKHIT16= 2.5342 / Tel Value High-Clock CLKHIT2= 4.0234 / Tel Value High-Clock CLKHIT3= 4.0283 / Tel Value High-Clock CLKHIT4= 5.0195 / Tel Value High-Clock CLKHIT5= 1.0352 / Tel Value High-Clock CLKHIT6= 4.0283 / Tel Value High-Clock CLKHIT7= 0.0488 / Tel Value High-Clock CLKHIT8= 2.5342 / Tel Value High-Clock CLKHIT9= 4.0430 / Tel Value High-Clock CLKLO1= 0.0000 / Set value Low-Clock CLKLO10= 0.0000 / Set value Low-Clock CLKLO11= 0.0000 / Set value Low-Clock CLKLO12= 5.0000 / Set value Low-Clock CLKLO13= 1.0000 / Set value Low-Clock CLKLO14= 4.0000 / Set value Low-Clock CLKLO15= 0.0000 / Set value Low-Clock CLKLO16= 9.7500 / Set value Low-Clock CLKLO2= 0.0000 / Set value Low-Clock CLKLO3= 0.0000 / Set value Low-Clock CLKLO4= 5.0000 / Set value Low-Clock CLKLO5= 1.0000 / Set value Low-Clock CLKLO6= 4.0000 / Set value Low-Clock CLKLO7= 0.0000 / Set value Low-Clock CLKLO8= 9.7500 / Set value Low-Clock CLKLO9= 0.0000 / Set value Low-Clock CLKLONM1= 'clk1Lo pmc' / Name of Low-Clock CLKLONM10= 'clk10Lo FrameStart' / Name of Low-Clock CLKLONM11= 'clk11Lo UcResetEnable' / Name of Low-Clock CLKLONM12= 'clk12Lo VHiRowEnable' / Name of Low-Clock CLKLONM13= 'clk13Lo VLoRowEnable' / Name of Low-Clock CLKLONM14= 'clk14Lo VHiReset' / Name of Low-Clock CLKLONM15= 'clk15Lo VLoReset' / Name of Low-Clock CLKLONM16= 'clk16Lo VpOut' / Name of Low-Clock CLKLONM2= 'clk2Lo FrameStart' / Name of Low-Clock CLKLONM3= 'clk3Lo UcResetEnable' / Name of Low-Clock CLKLONM4= 'clk4Lo VHiRowEnable' / Name of Low-Clock CLKLONM5= 'clk5Lo VLoRowEnable' / Name of Low-Clock CLKLONM6= 'clk6Lo VHiReset' / Name of Low-Clock CLKLONM7= 'clk7Lo VLoReset' / Name of Low-Clock CLKLONM8= 'clk8Lo VpOut' / Name of Low-Clock CLKLONM9= 'clk9Lo pmc' / Name of Low-Clock CLKLOT1= 0.0537 / Tel Value Low-Clock CLKLOT10= 0.0488 / Tel Value Low-Clock CLKLOT11= 0.0439 / Tel Value Low-Clock CLKLOT12= 4.9512 / Tel Value Low-Clock CLKLOT13= 1.0352 / Tel Value Low-Clock CLKLOT14= 4.0234 / Tel Value Low-Clock CLKLOT15= 0.0439 / Tel Value Low-Clock


VISTA Data Flow System
HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO ESO DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET DET VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2 VOLT2

Data Reduction Doc: Library Design Issue:
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VIS-SPE-IOA-20000-0010 1.6pre6 2006-12-12 144 of 145

CLKLOT16= 9.4678 / Tel Value Low-Clock CLKLOT2= 0.0488 / Tel Value Low-Clock CLKLOT3= 0.0488 / Tel Value Low-Clock CLKLOT4= 4.9609 / Tel Value Low-Clock CLKLOT5= 1.0449 / Tel Value Low-Clock CLKLOT6= 4.0283 / Tel Value Low-Clock CLKLOT7= 0.0488 / Tel Value Low-Clock CLKLOT8= 9.4678 / Tel Value Low-Clock CLKLOT9= 0.0586 / Tel Value Low-Clock DC1 = -2.3600 / Set value DC-Voltage DC10 = -3.3500 / Set value DC-Voltage DC11 = 0.0000 / Set value DC-Voltage DC12 = 0.7000 / Set value DC-Voltage DC13 = 0.7000 / Set value DC-Voltage DC14 = 3.5000 / Set value DC-Voltage DC15 = 2.2000 / Set value DC-Voltage DC16 = 3.3000 / Set value DC-Voltage DC2 = -3.3500 / Set value DC-Voltage DC3 = 0.0000 / Set value DC-Voltage DC4 = 0.7000 / Set value DC-Voltage DC5 = 0.7000 / Set value DC-Voltage DC6 = 3.5000 / Set value DC-Voltage DC7 = 2.2000 / Set value DC-Voltage DC8 = 3.3000 / Set value DC-Voltage DC9 = -2.3600 / Set value DC-Voltage DCNM1 = 'DC1 VIdle' / Name of DC-voltage DCNM10= 'DC10 VSlew' / Name of DC-voltage DCNM11= 'DC11 VRstUc' / Name of DC-voltage DCNM12= 'DC12 VDetCom' / Name of DC-voltage DCNM13= 'DC13 VnUc' / Name of DC-voltage DCNM14= 'DC14 VpUc' / Name of DC-voltage DCNM15= 'DC15 VnOut' / Name of DC-voltage DCNM16= 'DC16 RefBias' / Name of DC-voltage DCNM2 = 'DC2 VSlew' / Name of DC-voltage DCNM3 = 'DC3 VRstUc' / Name of DC-voltage DCNM4 = 'DC4 VDetCom' / Name of DC-voltage DCNM5 = 'DC5 VnUc' / Name of DC-voltage DCNM6 = 'DC6 VpUc' / Name of DC-voltage DCNM7 = 'DC7 VnOut' / Name of DC-voltage DCNM8 = 'DC8 RefBias' / Name of DC-voltage DCNM9 = 'DC9 VIdle' / Name of DC-voltage DCTA1 = -2.3535 / Tel Value 1 for DC DCTA10= -3.3447 / Tel Value 1 for DC DCTA11= 0.0049 / Tel Value 1 for DC DCTA12= 0.7031 / Tel Value 1 for DC DCTA13= 0.7031 / Tel Value 1 for DC DCTA14= 3.4961 / Tel Value 1 for DC DCTA15= 2.1973 / Tel Value 1 for DC DCTA16= 3.2959 / Tel Value 1 for DC DCTA2 = -3.3447 / Tel Value 1 for DC DCTA3 = 0.0049 / Tel Value 1 for DC DCTA4 = 0.6982 / Tel Value 1 for DC DCTA5 = 0.6982 / Tel Value 1 for DC DCTA6 = 3.4961 / Tel Value 1 for DC DCTA7 = 2.1973 / Tel Value 1 for DC DCTA8 = 3.2959 / Tel Value 1 for DC DCTA9 = -2.3535 / Tel Value 1 for DC DCTB1 = -2.3438 / Tel Value 2 for DC DCTB10= -3.3057 / Tel Value 2 for DC DCTB11= 0.0049 / Tel Value 2 for DC DCTB12= 0.6982 / Tel Value 2 for DC DCTB13= 0.7031 / Tel Value 2 for DC DCTB14= 3.4912 / Tel Value 2 for DC DCTB15= 2.1826 / Tel Value 2 for DC DCTB16= 3.2910 / Tel Value 2 for DC DCTB2 = -3.3057 / Tel Value 2 for DC DCTB3 = 0.0049 / Tel Value 2 for DC DCTB4 = 0.6982 / Tel Value 2 for DC DCTB5 = 0.6982 / Tel Value 2 for DC DCTB6 = 3.4912 / Tel Value 2 for DC DCTB7 = 2.1777 / Tel Value 2 for DC DCTB8 = 3.2910 / Tel Value 2 for DC DCTB9 = -2.3438 / Tel Value 2 for DC


VISTA Data Flow System
HIERARCH HIERARCH HIERARCH HIERARCH HIERARCH INHERIT PV2_1 PV2_2 PV2_3 PV2_4 PV2_5 END ESO ESO ESO ESO ESO =T = = = = =

Data Reduction Doc: Library Design Issue:
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VIS-SPE-IOA-20000-0010 1.6pre6 2006-12-12 145 of 145

DET WIN NX = 2048 / # of Pixels in X DET WIN NY = 2048 / # of Pixels in Y DET WIN STARTX = 1 / Lower left X ref DET WIN STARTY = 1 / Lower left Y ref DET WIN TYPE = 0 / Win-Type: 0=SW/1=HW / Extension inherits primary header 1. / WCS parameter value term 0. / WCS parameter value term 42. / WCS parameter value term 0. / WCS parameter value term 0. / WCS parameter value term

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