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Space Telescope Imaging Spectrograph
Slit Wheel Reapeatability

STIS Cycle-17 Calibration Phase-1 Template

Last Revised: February 19, 2009
Proposal ID:  11851
Title: Slit Wheel Repeatability
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 66 weeks) 

Total Prime Orbits:             0
External Parallel Orbits:       0
Internals or no-impact orbits:  1
Comments on orbit estimate:   perform one time


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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:     To check the stability of the STIS slit wheel by taking a 
sequence of comparison lamp spectra with grating G230MB/2697 and 3 different 
slits.                   

Description:    Verify the repeatability of the slit wheel for 3 STIS slits 
(52X0.2, 52X0.1, and 52X0.05) by taking images with the LINE lamp. Use the 
G230MB/2697 and rotate the slit wheel among the 3 chosen slits.                

Accuracy:   0.1 pixels

Comments on Accuracy:           

Products:   ISR


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# Link to Cycle 17 Science
# Use the GO + GTO Phase 1 exposure  listing and derived statistics
# posted on WWW.

Fraction of science programs supported by this calibration:     70%

List categories of science which can't be executed until after this proposal:
why:

List categories of science which are best performed contemporaneous with 
this proposal:
why:


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# THE REST OF THIS FORM IS FOR INTERNAL USE
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Observation summary: 
Verify the repeatability of the slit wheel for 3 STIS slits (52X0.2, 52X0.1,
and 52X0.05) by taking images with the Pt/Cr/Ne LINE lamp and the CCD 
detector. Use the G230MB (2697) grating with the CCD, and rotate the slit 
wheel among the 3 chosen slits. Detector: CCD Grating: G230MB (2697) Slits: 
52x0.2, 52X0.1, 52X0.05 Grating A: 52X0.2 (10 seconds) Grating B: 52X0.1 
(10 seconds) Grating C: 52X0.05 (20 seconds) Sequence: A-B-C-B-C-A-A-B-A-C-
B-B-A-B-C-B-C-C-A-B-A-C-B-A Forward motion: B - 4 times C - 6 times 
Backward motion: A - 6 times B - 4 times No motion: A/B/C - 1 time

# Target information (copy for each target)

Target Name.............................: LINE	
RA......................................: N/A		
Dec.....................................: N/A	
Flux (and units)........................: N/A	
Visibility window (if known or relevant): N/A
Comment on choice of target:

# Exposure list plan at the Phase I level. Be as complete as reasonable. 
# If possible information should be complete enough to allow easy 
# submission of a Phase 2 from this form. However, if you have to leave
# some of the fields blank below, or want to provide the information
# in another format, that is acceptable. (Make sure you do the BOP checking
# though, as this is a phase-1 issue.)

Table of exposures (copy for each exposure as appropriate/desired):

Target or lamp..........................: e.g. Pt/Cr/Ne Lamp
Type of Acquisition.....................: e.g. N/A
Detector for observation................: e.g. CCD
Operating mode .........................: e.g. ACCUM
Spectral Element........................: e.g. G230MB
Aperture................................: e.g. 52x0.2, 52x0.1, 52x0.05
Central Wavelength......................: e.g. 2697
Exposure Time...........................: e.g. 10, 20s 
Number of Iterations ...................: e.g. 1
BOP Predicted Local Count Rate for MAMA.: N/A
BOP Predicted Global Count Rate for MAMA: N/A
ETC PID IDs for Count Rates.............: N/A
Special Requirements or options.........: NON-INT
Comments: (e.g. if monitoring, specify frequency) perform once early 
in the cycle 

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# Special needs of this proposal?

Scheduling: Between August 1, 2009 and August 31, 2009

Prerequisites: none

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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# Analysis Plan

Expected FTE weeks for analysis:            0.2 (2 FTE Days)
Required turnaround on analysis (weeks):    4
Data volume (Mb needed for analysis):       24 CCD images at 10.5Mb each
                                            252Mb

Special software needed for analysis? (Describe):          none

Description of analysis Plans:	(1-2 paragraphs)
After processing by calstis, the SHIFTA1 and SHIFTA2 keywords will
be examined to determine the relative offsets for each exposure in
each slit.  An examination of the offsets as a function of time will
determine the repeatability of the slit wheel.