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: http://www.eso.org/~chummel/midi/ews/guide.html
Дата изменения: Thu Oct 21 18:03:45 2004 Дата индексирования: Sat Dec 22 20:11:06 2007 Кодировка: Поисковые слова: п п п п п п п п п п п п п п п п |
Gentlemen and Ladies
Below a description of the EWS (Expert Work Station:
pronounced "Ooze") software for coherent estimation
of MIDI visibilities. The package consists of C-routines
that do most of the work and IDL front-ends for selecting
data and viewing results.
Walter
11-Aug-2003
CONTENTS:
I. Summary of C-Language programs
II. Summary of tcsh scripts calling C-Language Programs
III. Summary of IDL routines calling tch scripts
IV. More details about (I)
V. More details about (II)
VI. More details about (III)
VII. Description of file selection GUI (Gorgonzola)
VIII. Standard file names and contents used by scripts
I. Summary of C-language programs and calling sequences:
1. oir1dCompressData "inFiles" maskFile outFile
2. oirFormFringes infile outfile [smooth]
3. oirRotateInsOpd infile outfile
4. oirGroupDelay infile outfile -s gSmooth
5. oirRotateGroupDelay infile delayFile outfile
6. oirAutoFlag infile delayFile flagFile [deltaOpd] [jumpOpd]
[nDrop]
7. oirAverageVis infile flagFile outFile
8. oirChopPhotometry "Afiles" "BFiles" maskFile outFile [nDrop]
9. oirRedCal sourceTag flux10
10. oirCalibrateVis targTag "calTags"
II. Summary of tcsh scripts that call these routines in an orderly fashion:
1. dispVis "infiles" maskFile outTag [fringeSmooth] [delaySmooth]
2. dispPhot "AFiles" "Bfiles" maskFile outTag
3. dispVisPhot "inFiles" "AFiles" "BFiles" maskfile outTag
4. dispVisSP "inFiles" refCoordFile crossFile outTag \
[-ndrop nDrop] [-smooth fringeSmooth] [-gsmooth delaySmooth] \
[-sigmaY sigmaY]
III. Summary of IDL procedures that call the oirRoutines
1. midiPipe, tag, mask=maskfile, files=filelist, smooth=smooth,
gsmooth=gsmooth
2. midiCalibrate, sourceTag, calTag, [photoTag=photoTag]
[,calFlux10=calFlux10], [,diam=diam] [,/noPoint] [,/print]
IV. More complete description of the oirRoutines:
1. oir1dCompressData "inFiles" maskFile outFile
Purpose:
Compress MIDI raw (PRISM/GRISM) files by multiplying each MIDI
window by a floating point mask (which has zeros in rows
not containing useful data) and summing in the y-direction
(perpendicular to the PRISM/GRISM dispersion). The result
is a 1-dimensional spectrum for each window region.
Parameters:
"inFiles" a list of raw MIDI (PRISM/GRISM) input files representing
one exposure. There may be more than one file because they
were broken up into 100MB files by the on-line system.
If there is more than one file they should be separated
by spaces and included between double quotes: "file1 file2 file3"
maskFile: a MIDI style FITS binary table whose imaging_data section
contains the masks described above. If this is not
specified it defaults to an environmental variable specified
externally (typically in the vltisetup script):
for PRISM/HIGH_SENS $prismhmask
for PRISM/SCI_PHOT $prismsmask
for GRISM/HIGH_SENS $grismhmask
for GRISM/SCI_PHOT $grismsmask
outFile: the name of the output file. This will be a MIDI style
FITS binary table in exactly the same format as "inFiles" and
maskFile except that the y-dimension of each DATA array is 1.
2. oirCompressSPData -data "inFiles" -out outFile [-mask maskFile] \
[-ref refCoordFile] [-nDrop dropPoints]
Purpose: Compress SCI_PHOT interferometry data as input to
oirFormFringes
Parameters:
"inFiles": blank-separated string of file names containing
input interferometric/photometric data in SCI_PHOT mode.
outFile: name of file to contain compressed data
maskFile (optional) file indicating relative weight
of pixels in compressing signal. This is typically
the output of oirSciPhotometry. If not specified,
no masking is applied.
refCoordFile: (optional) a FITS file containing an "imaging_detector"
table specifying the wavelength scale and curvature information for
the detector in the observed mode. If not specified this is taken
from "inFiles", but this is not sufficient for old input files where this
information was not correctly supplied at Paranal.
dropPoints: (optional) After a switch of chopping state
(Target-Sky-Target...) flag this many frames as "unknown"
state, in case there are small errors in the chopping timing.
Defaults to 0.
3. oirFormFringes inFile outFile [smooth]
Purpose:
Take the output of oirCompressSpec and form spectrally dispersed
fringes by subraction of the two interferometic channels and
supression of background. The latter is accomplished by
the subtraction itself and then by a high-pass filter (in
the time domain) applied to the individual spectral channels.
This removes instrumental and sky backgrounds that vary
more slowly than the fringe. The fringe should vary quickly
because of the OPD modulation imposed by the MIDI piezos.
Parameters:
inFile: name of the output from oirCompressSpec
outFile: output file name. The format is a MIDI style FITS table
imaging_data file with only one DATA region (
the combined I1-I2 channels).
smooth (optional) width of boxcar used in highpass filtering.
Default = 50
Data is smoothed with boxcar, and this smoothed version is subtracted
from input data yielding a highpass filter.
4. oirRotateInsOpd infile outfile
Purpose:
Remove the known Instrumental OPD components from the fringe spectra
that oirFormFringes produced. Each data point at frequency
k (in spatial units: 2 pi/lambda) is multiplied by exp(-i*k* OPD)
where OPD is the sum of the OPD from the MIDI piezos and the
VLTI delay lines.
Special Notes:
1. The result is a FITS imaging_data file in
"pseudo-complex" format. I.e. it is in REAL format
but each row is twice as long as the original data:
each value is a (real, imaginary) pair.
2. The VLTI Delay values may contain large fictitious
offsets of up to 1cm if the system was not correctly
zeroed at setup. To avoid applying these large
fictitious offsets, the program determines the
MODE of the tracking positions during the run and
subtracts this before applying the OPD shift. This
modal value is printed by the program and also
stored in the output header as "OPD0" in meters.
Parameters:
inFile: name of the output from oirFormFringes
outFile: output file name. The format is a MIDI style FITS table
imaging_data file in pseudo-complex format.
5. oirGroupDelay infile outfile -s gSmooth
Purpose:
Estimate the group delay for each measured spectrum. The
group delay is the peak of the Fourier Transform of the
spectrum (thus in the delay domain, not the frequency
domain). Each spectrum is fourier transformed. Note
that because the MIDI beam-combiner has only two output
phases it is essentially a cosine correlator and not
a complex correlator. This means that the group-delay
has TWO peaks: at positive and negative delays.
Because the actual OPD was modulated by the MIDI piezos
and this modulation was deRotated in oirRotateInsOpd,
one of the two peaks is nearly stationary from frame
to frame (only atmospheric OPD movement remains) while
the other peak moves around with TWICE the instrumental
modulation. Thus if we average a few frames together
the wrong side band is strongly suppressed. In this
program a gaussian smoothing of sigma = gSmooth frames
(default 4) used in this averaging.
Parameters:
infile: output of oirRotateInsOpd
outFile: output file containing TWO interesting tables:
1. A pseudo-complex imaging_data table containing
the raw FFTs of the input data
2. A DELAY table containing the value of the peak
delay (after smoothing) of the above table at
each frame. This DELAY table has three columns:
TIME (same as raw data), TELESCOPE (always 1,2)
and DELAY (peak of group delay, with OPD0 added),
in seconds (IAU standard). Thus you have to
multiply by the speed of light to get meters.
3. gSmooth if specified can change the smoothing
in the frame domain before looking for a delay
peak. Default is gaussian sigma = 4 frames.
Choose larger for weak sources in good weather,
shorter for strong sources in bad weather.
6. oirRotateGroupDelay infile delayFile outfile
Purpose:
Remove the group delay measured by oirGroupDelay as
well as the instrumental OPD from fringe data
(the output of oirFormFringes). Same algorithm
as specified in oirRotateInsOpd.
Additionally estimate an offset PHASE for each
frame and remove it. This phase is primarily
the result of water vapor dispersion (i.e.
non-constant index of refraction). Several
spectra are averaged together to remove the
beats from the off-side-band, then the
phase offset is determined and removed. The
smoothing is a rolling gaussian filter with
sigma = 6 pixels.
Parameters:
infile: output of oirFormFringes
delayFile: output of oirGroupDelay
outfile: output, in format identical with
output of oirRotateInsOpd
7. oirAutoFlag infile delayFile flagFile [deltaOpd] [jumpOpd]
[nDrop]
Purpose:
Try to choose (automatically) which frames to include in the output
visibility estimation: This is currently NOT done on the basis of
estimated amplitude since this biases the result. The current
criteria are:
1. OPD tracking distance from 0-point. Experience shows significant
attenuation of fringe (a few procent) for PRISM if this is larger
than about 150 microns. So if ABS(instrumental OPD-group OPD) >
deltaOpd the frame is flagged.
2. Jumps in OPD. There are some instrumental OPD jumps (due to
telescope refocusing) where the fringe is presumably attenuated.
If the 2nd difference in the group OPD is > jumpOpd the frame is
flagged.
3. In addition, nDop points on either side of jumps are flagged.
Output is written into a FLAG Fits table that specifies the flagged
time intervals.
Parameters:
inFile: output of oirFormFringes (only used to read instrumental
OPD)
delayFile: output of oirGroupDelay
flagFiile: name of file to contain FLAG tables
8. oirAverageVis infile flagFile outFile
Purpose:
Average all unflagged but phase rotated frames together to arrive
at a single (complex) visibility.
Output is in IAU/ESO OI_VIS format FITS tables which is different
from imaging_data. These can be accessed with my IDL oirGetVis
routine: data_array = oirGetVis(file, wave=wave) where
wave contains the channel wavelengths in microns. data_array
is an array of structures containing (among other things)
visamp and visphi (amplitude and phase).
Parameters:
infile: output of oirRotateGroupDelay
flagFile: output of oirAutoFlag (or manual flagging)
outFile: name of OI_VIS file
9. oirChopPhotometry "Afiles" "BFiles" maskFile outFile [nDrop]
Purpose:
Reduce separate chopping photometry observations for use
in normalizing visibilities. An estimate of sky is made
and removed from arrays. They these are summed in the y-direction
both with and without Masking (as described in oirCompressSpec).
The mask should be IDENTICAL with the one specified there.
Input are two separate (sets of) files containing raw chopping
data for AOPEN and BOPEN shutter positions.
Output is a imaging_data FITS table file with 12 rows, each row
containing a single DATA1 array:
1. Total Flux (ADU/s/channel) for AOPEN shutter position
2. Total Flux (ADU/s/channel) for BOPEN shutter position
3. Total Flux GeometricMean of A&B (i.e. of rows 1 and 2).
4. Masked Flux (ADU/s/channel) for AOPEN shutter position
5. Masked Flux (ADU/s/channel) for BOPEN shutter position
6. Masked Flux GeometricMean of A&B (i.e. of rows 4 and 5).
7-12 are the (poorly) estimated rms of the above quantities.
Parameters:
"AFiles" black separated list of AOPEN chopped photometry files
"BFiles" black separated list of BOPEN chopped photometry files
maskFile mask as described in oirCompressSPec
outFile FITS imaging_data file containing output
10. oirRedCal sourceTag
Purpose:
This program is somewhat different in purpose than the previous. It
takes the output files from several of the previous steps, as
applied to a calibrator and computes the instrumental visibility
and spectrophotometric calibration.
In this and the programs described below I use "tags" to identify
all the files belonging to one observation set. The full file
names are tag.type.fits where type describes the file type
(see complete listing below). Thus oirRedCal expects all
input files to have this type of name.
The output of oirRedCal is an OI_VIS table with 3 rows:
1. Instrumental visibility (amplitude and phase)
2. Spectrophotometric calibration (ADU/s/Jy)
3. "Strehl Ratio": not really, but the ratio of masked
counts/total counts per spectral channel.
Parameters:
sourceTag: the initial part of input file names, may also include a
directory. e.g. hd10380 or /strw11/jaffe/ngc4151
The type flags actually used are photometry (output of
oirChopPhotometry), and correlated flux (output of oirAverageVis),
thus the real file names would be hd10380.photometry.fits
and hd10380.corr.fits.
output: is not specified. The output is written into a file named
sourceTag.redcal.fits and contains the abovemention OI_VIS table.
11. oirSciPhotometry -data "inData" -ref refCoordDef -cross cross \
-out outFile -mask outMaskFile [-ndrop nDrop] [-sigma sigmaY]
Purpose:
Measure source photometry from chopped data in non-interferometric
SCI_PHOT channels. Simultaneously determine the best "mask" for
selecting photometric and interferometric data.
Parameters:
"data": blank-separated list of SCI_PHOT input data files
refCoordDef: FITS file containing "imaging_detector" table specifying
wavelength and curvature date for SCI_PHOT areas on detector
cross: FITS file containing cross-coupling coefficients ("kappa-coefficients")
between photometric and interferometric channels. Produced by
oirCrossCoeff
outFile: file name to receive photometry output. In same format as
output of oirChopPhotometry.
outMaskFile: file name to receive calculated mask. To be used as
input to oirCompressSPData
nDrop: (optional) as in oirCompressSPData, drop this many points
after change of chopping state
sigmaY: (optional) sigma (standard deviation) width of gaussian mask weights
in the Y-direction. Defaults to 2.0
12. oirCalibrateVis targetTag calTag [-sp spTag] [-calflux calFlux10]
[-cald calDiameter] [-noPoint]
Purpose:
Combine reductions of a target and calibrator observations to produce
calibrated visibilities and plots. The output is two FITS table files.
1. An OI_VIS table file: targetTag.calvis.fits containing one
row per input row in the file targetTag.corr.fits
This contains calibrated visamp and visphi.
2. An imaging_data file: targetTag.calphot.fits containing two
rows:
1. calibrated photometry (Jy) under mask
2. calibrated photometry (Jy) total
Parameters:
targetTag: descriptor for science target. The types actually
used are .photometry and .corr
calTag: descriptor for calibrator. The type actually used
is .redcal
output is as described above: targetTag.calvis and .calphot
-sp spTag : if specified use this calibrator tag to define
a spectrophotometric calibrator different from the visibility
calibrator. Use this if the flux/spectrum of the visibility
calibrator are unknown are inappropriate for photometric
calibration.
-calflux calFlux10: specify the flux of the calibrator used
for flux calibration in Jansky at 10 microns. A Rayleigh-
Jeans spectrum is assumed. If not specified 1 Jy is used.
-cald calDiameter: visibility calibrator diameter in milliarcsec.
If not specified 0.0 mas is used.
-noPoint: Do not assume that the target is unresolved by the
single telescope PSF. The effect is that correlated
fluxes are computed as: visibility*(flux under mask) instead
of visibility * (total flux in window)
13. oirCrossCoeff "Afiles" "Bfiles" coordFile outFile nDrop
Purpose: calculate cross-coupling coefficients (kappa coefficients)
for SCI_PHOT mode data
Parameters:
"Afiles" blank-separated string of input files of a star
taking in chopping photometry mode with the B-shutter closed
"Bfiles" blank-separated string of input files of a star
taking in chopping photometry mode with the A-shutter closed
coordFile: FITS file containing "imaging_detector" table specifying
distortions and wavelength information for this SCI_PHOT detector
mode.
outFile: output file name. Used by oirSciPhotometry.
nDrop: see oirCompressSPData or oirSciPhotometry
V. tcsh scripts that call the oir routines in an orderly fashion using the
"tag"."type" fields to communicate file names:
1. dispVis "infiles" maskFile outTag [fringeSmooth] [delaySmooth]
Performs in sequence:
oir1dCompressData+oirFormFringes+oirRotateInsOpd+oirGroupDelay+
oirRotateGroupDelay+ oirAutoFlag+oirAverageVis
Parameters:
"infiles" blank separated list of interferometric files
maskFile as described in oirCompressSpec
outTag first component of file names to use for output;
may include directory path
fringeSmooth high pass filter width used in oirFormFringes
(c.f. above)
delaySmooth smoothing gaussian width used in oirGroupDelay
(c.f. above)
2. dispPhot "AFiles" "Bfiles" maskFile outTag
Performs oirChopPhotometry using outTag to identify output file
Parameters:
see oirChopPhotometry except that outTag is only the first component
of output file name
3. dispVisPhot
Combines dispVis and dispPhot
Parameters:
"inFiles" "AFiles" "BFiles" maskfile outTag
4. dispVisSP "inFiles" refCoordFile crossFile outTag \
[-ndrop nDrop] [-smooth fringeSmooth] [-gsmooth delaySmooth] \
[-sigmaY sigmaY]
Performs in sequence:
oirSciPhotometry+oirCompressSPData+oirFormFringes+oirRotateInsOpd+oirGroupDelay+
oirRotateGroupDelay+ oirAutoFlag+oirAverageVis
to reduce SCI_PHOT mode data.
Parameters:
"infiles" blank separated list of interferometric files
refCoordFile file containing "imaging_detector" table with
optical distortion information
crossFile file containing kappa coefficients
outTag first component of file names to use for output;
may include directory path
fringeSmooth high pass filter width used in oirFormFringes
(defaults to 50)
delaySmooth smoothing gaussian width used in oirGroupDelay
(defaults to 6.0)
sigmaY s.d. width in y-direction of mask function
(defaults to 2.0)
VI. IDL procedures that call the above programs:
1. midiPipe, tag [,files=filelist] [,mask=maskfile] [,smooth=sm]
[,gsmooth=gsm]
Purpose:
run dispVisPhot and oirRedCal on 3 files specifying interferometric and
photometric raw data.
Parameters:
tag: output tag to identify files to dispVisPhot
files (optional) a string array of 3 input file names, each of which
may be a blank-separated list of files.
If files is not specified, the GORGONZOLA GUI will come up to allow
manual specification of files
mask (optional): mask file name. If not specified a default
depending on the instrumental setup. For old prism high_sens
files (before Dec 2003) use: mask=getenv('prismomask')
smooth:Delay high-pass smoothing width to supress background
fluctuations. Default is 50 but use a smaller value if
your source is very weak.
gsmooth: group delay estimation averageing half-width (frames). Default
is 4 but use larger value for weak sources during stable atmospher,
smaller for strong sources during rapid OPD changes. For weak
sources during rapid OPD changes, give up.
2. midiSPipe, tag, files [,smooth=smooth] [,gsmooth=gsmooth] $
[,coord=coord] [,cross=cross] [,ndrop=ndrop] [,sigmay=sigmay]
Purpose: run dispVisSP to reduce SCI_PHOT data
Parameters: as in midiPipe with the addition of:
coord: file containing distortion/wavelength information
for individual MIDI channels, not yet included automatically
with data from Paranal. Defaults to either of :
$drsRoot/software/minrts/config/mioSetup_FIELD_PRISM_SCI_PHOT_SLIT.tmp
$drsRoot/software/minrts/config/mioSetup_SPECTRAL_GRISM_SCI_PHOT_SLIT.tmp
cross: file containing kappa/cross-coupling coefficients.
defaults to one of:
$drsRoot/software/minrts/config/mioKappa_FIELD_PRISM_SCI_PHOT.fits
$drsRoot/software/minrts/config/mioKappa_SPECTRAL_GRISM_SCI_PHOT.fits
3. midiCalibrate sourceTag calTag
Purpose:
run oirCalibrateVis with specified parameters. In addition a whole
bunch of plots is produced in a file named sourceTag.ps.
VII. File Selection GUI: Gorgonzola
EWS includes a data selection GUI, somewhat like GASGANO.
To browse your raw data, and select some of it type:
FileList = midiGui()
There are alternate versions described below.
There is a faster version that caches the contents of the file
headers on disk, but it only works if you have write permission
on the data disks:
FileList = midiGuis()
Note that IDL is indifferent to upper/lower case letters in commands
and variable names (but not indifferent to case in FileNames)
It brings up a GUI and returns a list of files selected.
*******************************************************************
USING THE GUI.
The gui is pretty spartan. Up at the top there are 10 buttons that
let you select files, modify the display a bit, and quit.
Below this there is a scrollable area that shows information on
each of the available files and on the left
a column of ASTERISKs (*) showing which files are currently selected,
or blanks if they are not. Initially files are brought up all un-selected.
In the next column you see the file name.
NOTE: Due to ESO limitations on file lengths, MIDI files cannot be
longer than 100 MB or so, while a single observations may generate
Gigabytes of data. The on-line data system breaks the data up
into 100 MB files. Gorgonzola recognizes this process, and the
displayed file name is only the FIRST file of all the files that
constitute an observation. When Gorgonzola returns, all the sub-files
for an observations are concatenated into a single character string
with spaces between the file names. Most of the EWS programs can
recognize such a string and process the files sequentially.
NOTE further, however, that if you use such a string to call a
C-program directly (e.g. oir1dCompressData), you have to enclose
the concatenated string in double quotes "...".
The other columns show keyword values for each observations, gleaned from
the file primary FITS headers.
WHAT YOU CAN DO IN THE LOWER scrollable AREA with all the keyword data:
Two things:
1. If you click on the leftmost raised button you
can manually select or deselect single files.
2. If you click on one of the data cells that show
keyword values, that value is "caught" and displayed
up on the top; both its keyword and its value.
The "caught" values can be used for massive selection
and de-selection as described under BOOLEAN buttons below.
WHAT THE TOP BUTTONS DO:
We start with the easy ones:
QUIT causes the GUI to leave without making a selection
SELECT causes the GUI to leave and returns the selected files
UP/DOWN IDL and X-windows crash if thousands of widgets are put
on the screen, so I have limited the display to 100 rows.
If the rows you want to see are outside this range you
can push UP or DOWN to scroll. NOTE that the scroll bar
on the right only allows scrolling within the 100 displayed
rows.
HIDE Remove all currently unselected rows from the display. This
can considerably simplify things if you've already de-selected
a lot of files.
SHOW Reverse of HIDE: show all files, selected or not. This gives
you the opportunity to selectively re-select unselected files.
Sometimes the first few non-selected files are not displayed
after hitting the SHOW button. Try clicking the UP button.
To the right of this row the current HIDE/SHOW mode is displayed
Then the real meat: the BOOLEAN buttons.
These are not strictly boolean but sort of.
When you click one of them, the "caught" value
is compared to all other values in the same column
and the currently list of selected files is modified:
In the second row down on the GUI are six comparison operators:
= Equal
!= Not Equal
> Greater than
< Less than
<= Greater than or equal
> Less than or equal
To the right of this row the currently selected comparison is shown.
In the third row two combination operators:
AND The results of the comparison are
logically ANDed with the current selection
OR The results of the comparison are
logicall ORed with the current selection
Confused? It actually works fairly intuitively.
Suppose you have made a hundred or so exposures during a day, and
suppose you are looking for a group of exposures with the PRISM
in HIGH_SENS mode. The fifth column of selction buttons is labelled
"INSGRIS" (shortend from INS GRIS NAME). Look down this column, with
the slider if necessary until you find a button with PRISM displayed.
Click on this and the words INGRIS and PRISM should appear below the
AND/OR buttons to indicate your selection. Now click on the OR
button. All observations with GRIS=PRISM are ORed with the
initial selection (i.e. nothing), and asterisks should appear in
the left hand column of all PRISM observations.
Now click on HIDE and all non-PRISM observations should disappear.
Now go down the INSOPT1 column and find an observations with
OPT1=HIGH_SENS. Click on this, and then on AND. This will
AND the set of HIGH_SENS observations with the current PRISM selection
and any SCI_PHOT or OPEN observations should disappear. You
can continue by selecting on OBSTARG (target name as given by
the observer) or NRTSMODE (what the online program thought it
was doing), or FILTER or SHUTTER position.
Using the other relational buttons, you can also select by time, because
the file names are ordered by time.
For example you can click on the file name of first observation you want, then
click on the >= button and then on AND. All the earlier files will be
deselected. Then you can click on the last observation, the <= button
and AND, and the later observations will disappear.
When you have made the selection you want, click on SELECT.
At the top right the total number of files in the list,
and the total number currently selected, are displayed.
COMMON PITFALLS:
If you click on a data item and then click HIDE, not much
will happen (except that previously de-selected rows may
disappear). You first have to press on of the boolean
buttons to make something change.
******************************************************************
ALTERNATIVE calling sequences:
files = midiGuiS()
Look for a file in the search directory called midiGui.SAV, and
if you find it, assume that it contains the keyword values for
all the MIDI files in this directory. This speeds things up
a lot. If you don't find it, parse all the headers and store
the summary in the abovenamed file upon exit. This will
crash if you don't have write privliges.
If you can added/deleted files in the directory, so that the
cached version is not up to date, just delete it and
try midiGuiS again.
files = midiGui(dir=datadir) or midiGuiS(dir=datadir)
gorgonzola assumes that idl is running in the directory
where the data is. If this is not the case you can
use the above forms to specify a different data directory.
You can also use the IDL utility pushd:
pushd, datadir
files = midigui()
popd
******************************************************************
VIII. Standard file names and types, and lower level access programs
The following standard file types are produced by the specified programs.
Some notes indicate how to access the contents of the programs:
Some of the lower level programs to access this data are described below
but almost all are listed here:
oirGetData(dataFileName [,rows] [,col=col],[ierr=ierr])
Get raw or semi-reduced detector data
oirGetVis(visFileName [,wave=wave])
Get reduced visibility data and wavelength information
oirGetDelay(groupDelayFileName)
Get estimated group delay for each reduced frame
oirGetOpd(fileName)
From raw or partially reduced data get piezo+VLTI delay
line OPD position
oirGetMeanRMS(inputfile)
Take pixel by pixel mean and rms of all frames in an observation
oirGetDetector(fileName)
Get data from IMAGING_DETECTOR table, specifying detector layout
oirGetWaveNo(detectorFile, region)
Get wavenumbers (here defined as 2*!pi/lambda(micron)) for
each pixel in specified detector region (1-relative)
midChopImage (datafile)
Return 2-row structure with mean of Target- mean of Sky
detector images in first row, and mean of Sky in 2nd row.
File types:
.compressed
Produced by oirCompressSpec, contains a header, an imaging_detector table
and a floating point imaging_data table. The last has a 1-dimensional
DATAn array for each input frame for each detector window.
This can be accessed with oirGetData(dataFileName).
dataArray = oirGetData(dataFileName)
oirGetData works on raw and partially reduced detector data.
It returns an array of structures. Each structure corresponds to
one data frame, and corresponds to ESO FITS interferometry
data tables. Each row of the table contains information on
the time of exposure (MJD days), exposure time (sec), OPD positions,
chopping mirror positions, and finally the data itself.
dataArray[15].time contains the MJD time of the 16th frame
(IDL is 0-relative).
dataArray.data1 is in general a 3-dimensional data cube, where
each plane represents the detector data from the 1st specified
detector region, and the 3rd dimension is frame number.
The data arrays are INT for raw data and FLOAT for partially
reduced data. Note that the raw data (16-bit integers) is
offset by -32768 from the true detector zero values.
.fringes
Produced by oirFormFringes, contains a header, an imaging_detector table
and a imaging_data table with a single DATA1 array for each input frame.
This can be accessed with
table = oirGetData(dataFileName)
data = table.data1
.insopd
Produced by oirRotateInsOpd. Contains a header and imaging_detector table,
and a pseudo-complex imaging_data table with a single DATA1 array per row.
Header contains keyword OPD0 describing offset subtracted from all
OPDs before rotation (=mode of tracking OPDs).
This can be accessed with
table = oirGetData(dataFileName).
data = pseudocomplex(table.data1)
data is them COMPLEX(nFrames, nFreq)
.groupdelay
Produced by oirGroupDelay. Contains a header and imaging_detector table,
and a pseudo-complex imaging_data table with the FFT of .insopd. The
header contains some special keywords:
OPD0: as in .insopd
OPD1,OPD2: coordinates of delay direction in output FFT. The delays
= OPD1 + OPD2*(xpix-1).
This table can be accessed with oirGetData(dataFileName). The
data section can be accessed using a call to pseudoComplex.
E.g.
gd = oirGetData('mydata.groupdelay.fits')
gdc = pseudocomplex(gd.data1)
gdc is COMPLEX(nFrames, 512), with the y-axis representing
delay.
Additionally there is a 3rd table DELAY containing (per frame) the
time (MJD days), telescope numbers and estimated OPD (seconds). This
can be accessed with oirGetDelay(fileName)
.ungroupdelay
Produced by oirRotateGroupDelay. Contains the usual header and
detector tables and a imaging_data table in pseudo-complex format.
Can be accessed with
ugd = oirGetData(filename)
ugdc = pseudocomplex(ugd.data1) which is COMPLEX(nFrame, nFreq)
Additionally there is a 3rd table DISPERSION containing (per frame)
the value of the average phase subtracted from each row. The
table has three columns "TIME" "TELESCOPE" and "DISPERSION", which
for the purpose at hand, is the subtracted mean phase in degrees.
This is accessed by the generic fitstable routines:
t = obj_new('fitstable', filename, extname='DISPERSION')
dispData = t->readrows()
obj_destroy,t
.flag
Produced by oirAutoFlag. Contains a header and a FLAG table with the
time intervals that have been flagged. There is no oirGetFlag routine.
You can use:
t = obj_new('fitstable', filename, extname='FLAG')
flagData = t->readrows()
obj_destroy,t
.corr
Produced by oirAverageVis. Contains a header, an OI_WAVELENGTH table
specifying the wavelength for each channel, and an OI_VIS table
containing averaged correlated fluxes.
Can be accessed with
visTable = oirGetVis(filename, wave=wave) with wave optional
visTable.visamp is an array of (nWave) correlated fluxes (Jy)
visTable.visphi is an array of (nWave) differential phases (degree)
visTable.visamperr contains the estimated rms of visamp
visTable.visphierr contains the estimated rms of visphi
wave contains nWave values of the wavelength (microns)
.photometry
Produced by oirChopPhotometry. Header, detector tables, and
imaging_data table in float format
Can be accessed with photData = oirGetData(filename)
photData[0].data1 contains the photometry data for telescope A
photData[1].data1 contains the photometry data for telescope B
and so forth (see heading oirChopPhotometry above)
.redcal
Produced by oirRedCal. Header, OI_WAVELENGTH and OI_VIS tables
Can be accessed with oirGetVis(filename, wave=wave)
.calphot
Produced by oirCalibrateVis. Header, detector, imaging_data table
Can be accessed with oirGetData(filename)
.calvis
Produced by oirCalibrateVis. Header, detector, imaging_data table
Can be accessed with oirGetVis(filename, wave=wave)