STIS Cycle-17 Calibration Phase-1 Template
Last Revised: February 19, 2009
Proposal ID: 11848
Title: CCD Read Noise Monitor
PI: Michael A. Wolfe
Co-I(s): Rachel Osten
Charles Proffitt
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# Orbit estimates are TOTAL for all of cycle-17; assume 18 weeks)
# 03 August 2009 to 12 September 2010
Total Prime Orbits: 0
External Parallel Orbits: 0
Internals or no-impact orbits: used 18 allowed 20
Comments on orbit estimate: Orbits will occur every month
for the first four months (Aug 2009 - Nov 2009) and continue bi-monthly
until September 2010.
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# This section should be written with a GO audience in mind -- use
# Calibration plans in WFPC-2 handbook as a guide.
Purpose: Monitor the read noise in all of the on-chip amplifiers
(A,B,C,D) to track changes affecting the STIS CCD.
Description: This proposal measures the read noise of the STIS CCD
using pairs of bias frames. All amplifiers (A, B, C, D) are used. Full
frame and binned observations are made in both Gain 1 and Gain 4,
with binning factors of 1x1, 1x2, 2x1 and 2x2.
Accuracy: 0.05DN
Comments on Accuracy: 0.05DN
Products: ISR, updates to calibration reference files.
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# THE REST OF THIS FORM IS FOR INTERNAL USE
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# Target information (copy for each target)
Target Name.............................: n/a (internal)
RA.............................................: n/a
Dec...........................................: n/a
Flux (and units)........................: n/a
Visibility window (if known or relevant): n/a
Comment on choice of target: n/a
# Table of exposures (copy for each exposure):
Target or lamp..........................: BIAS
Type of Acquisition.....................:
Detector for observation................: STIS/CCD
Operating mode .........................:
Spectral Element........................: DEF
Aperture................................: DEF
Central Wavelength......................:
Exposure Time...........................: 0
Number of Iterations ...................: 2
BOP Predicted Local Count Rate for MAMA.:
BOP Predicted Global Count Rate for MAMA:
ETC PID IDs for Count Rates.............:
Special Requirements or options.........: GAIN = 4, BINNING=1x2,2x1,2x2
AMP = A, B, C, D
Comments: Take exposure every month for first four months and then
bi-monthly after that..
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# Special needs of this proposal?
Scheduling: Schedule every month for the first four months and then bi-monthly
after that. Start on August 03, 2009.
Prerequisites: n/a
PDB update? no
On-board table update? no
# Special Requirements:
Real time? N
Special commanding? N
Quick Data turnaround? N
Special timing required? N
Other? N
Describe (& justify) special requirements:
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# Link to Cycle 17 Science
Fraction of science programs supported by this calibration: 60%
List categories of science which can't be executed until after this proposal:
none
why:
List categories of science which are best performed contemporaneous with
this proposal:
none
why:
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Expected FTE weeks for analysis: 2
Required turnaround on analysis (weeks): 2
Data volume (Mb needed for analysis): 10.5Mb
Special software needed for analysis? (Describe): Batchron
initially retrieves the gain setting, binning factor and number
of pixels from the bias headers to check that each bias frame
contain the same values. The firstbias frame is used as a reference.
A difference image is then produced from all the biases in each image
set. The difference image along with the reference image are then
used to acquire statistics from defined areas in the difference and
reference biases using the iraf package xdimsum.iterstat. The
statistics are the read noise (mean) and read noise uncertainty
(mean error of the mean). Using these statistics batchron creates
for each gain and bin setting output log and table files.
Description of analysis Plans: This proposal measures the read
noise of the STIS CCD using pairs of bias frames. All amplifiers
(A, B, C, D) are used. Full frame and binned observations are made
in both Gain 1 and Gain 4, with binning factors of 1x1, 1x2, 2x1
and 2x2.
