Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.stsci.edu/hst/stis/calibration/Cycle_22/13988.txt Дата изменения: Unknown Дата индексирования: Mon Apr 11 18:39:27 2016 Кодировка: IBM-866 Поисковые слова: http www.astronomy.ru forum index.php topic 4644.0.html

STIS Cycle-22 Calibration Phase-1

Last Revised: Aug 26, 2014
Proposal ID: 13988
Title: CCD Sparse Field CTE Internal
PI: Sean Lockwood
Co-I(s):

---------------------------------------------------------------------------
# Orbit estimates are TOTAL for all of cycle-22; assume 52 weeks
# 01 November 2014 to 01 January 2015

Total Prime Orbits: 0
External Parallel Orbits: 0
Internals or no-impact orbits: 82
Comments on orbit estimate: Orbits will occur between
01 November 2014 to 01 January 2015.


---------------------------------------------------------------------------
# This section should be written with a GO audience in mind -- use
# Calibration plans in STIS handbook as a guide.

Purpose: Re-establish an accurate correction for parallel register
CTE losses that can be used for direct analysis of science data with
negligible background. Do measurements for both GAIN settings
(1 and 4).


Description: The sparse field CTE will be measured via internal
calibration lamp observations taken through narrow slits. The
strategy of the test is as follows. Using the onboard tungsten
lamp, narrow slit images are projected at different positions
on the detector. At each position a series of exposures is
taken alternating between the тАШAтАЩ and тАШCтАЩ amplifiers for readout.
The further the charge needs to be shifted to be read out, the
more charge it will lose. For the parallel CTE measurement,
the test will use the the cross disperser slits: 0.05x31NDB and
0.05x31NDA. In order to test the effects of different bias
voltages the whole series of exposures are executed once for
GAIN=1, and once for GAIN=4; this process requires a total of
74 orbits which includes various sets of biases. For the CTE
pixel based correction, the test requires 8 orbits for darks
read out with amplifier A. All orbits < 1800s.


Accuracy: 1%

Comments on Accuracy: CTE correction coefficients will be determined
to a relative accuracy of 1%; photometry should not be limited to >1%
accuracy after correction for CTE.

Products: Determine slope for time dependent correction of CTE, possible
update of ccdtab reference file, and a summary in the end of cycle ISR.




---------------------------------------------------------------------------
# THE REST OF THIS FORM IS FOR INTERNAL USE
---------------------------------------------------------------------------
# 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..........................: TUNGSTEN
Type of Acquisition.....................: FLAT
Detector for observation................: STIS/CCD
Operating mode .........................: ACCUM
Spectral Element........................: G430M
Aperture................................: 0.05x31NDA
Central Wavelength......................: 5471
Exposure Time...........................: 0.3s, 0.6s, 0.9s, 2.3s
Number of Iterations ...................: 1
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=1,4, POS=3.2-[0,1,2,3,4]
Comments: Take exposures sequentially

Target or lamp..........................: TUNGSTEN
Type of Acquisition.....................: FLAT
Detector for observation................: STIS/CCD
Operating mode .........................: ACCUM
Spectral Element........................: MIRROR
Aperture................................: 0.05x31NDB
Central Wavelength......................:
Exposure Time...........................: 0.3s
Number of Iterations ...................: 1
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=1,4, POS=3.6-[0,1,2,3,4]
Comments: Take exposures sequentially

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 ...................: 2,3
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=1,4
Comments: Take exposures sequentially.

---------------------------------------------------------------------------
# Special needs of this proposal?

Scheduling: Schedule between 01 November 2014 and 01 January 2015. Start on
November 01, 2014.

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:


-------------------------------------------------------------------------
# Link to Cycle 22 Science

Fraction of science programs supported by this calibration:
26% of STIS total exposure time.

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:

---------------------------------------------------------------------------

Expected FTE weeks for analysis: 3
Required turnaround on analysis (weeks): 3
Data volume (Mb needed for analysis): 10.5Mb
Special software needed for analysis? (Describe): A script to determine
the flux and background.

Description of analysis Plans:
These CTI measurements are made using an "internal sparse field test",
along the parallel axis. This test utilizes the ability of the STIS CCD and
its associated electronics to read out the image with any amplifier, i.e.,
by clocking the accumulated charge in either direction along both
parallel and serial registers. A sequence of nominally identical exposures
is taken alternating the readout between amplifiers on opposite sides of
the CCD. Amplifier A and amplifier C are used to check the
parallel CTI at the default gain=1 and 4 setting. Comparison of the charge
readout using the A and C amplifiers yields a measure of the CTI. If there
were no CTI, then the ratio of the signals read out using the two different
amplifiers for a source at the same position would be identically 1.