WFC3 SMOV4 Analysis Plan: WF40-11453
1. ID
a.
b.
c.
d.
e.
SMOV Activity: WF40
Program ID: 11453
Title: IR Flat Field Uniformity
PI: B. Hilbert
Requirements addressed: 1.3.7
2. Expected Datasets
a. Number of external exposures: 72 full-frame external exposures
b. Number of external orbits: 9 external orbits
c. Number of internal exposures: 0
d. Number of internal visits: 0
3. Time criticality
a. Real time SMOV activities or impact on SMOV flow: none
b. Impact on WFC3 science operations readiness: none
c. Impact on WFC3 pipeline readiness/maturity: none
d. Impact on other calibrations (e.g. SIAF): Accurate flat fields are
necessary for calibrations in which photometry is performed.
e. Impact on ERO program: Accurate flats are necessary for the correct
calibration of ERO observations.
4. Analysis activities
a. One paragraph description: Data will be collected through 4 filters at
each of 9 positions on the sky. By measuring the relative brightness of
various stars at different positions on the detector, we will be able to
produce a map of the IR channel’s sensitivity.
b. SMOV data dependencies: Dark current ramps from SMOV testing will
have to be subtracted from the data prior to performing photometry. In
order to follow the positions of many stars in the 9 different pointings, an
accurate geometric distortion correction is needed.
c. Ground test data dependencies: none
5. Analysis team
a. Analysis lead
i. Name: Bryan Hilbert
ii. Day of effort to assess acceptability of dataset: 0.25
iii. Days of effort for time critical activities (if any): 0
iv. Days of effort for science readiness decision: 5
v. Days of effort for ISR generation: 2
b. Analysis Support
i. Name (s): none
6. Software tools
a. Name of code: Existing IRAF scripts will be used to measure the
positions and magnitudes of the sources in each observation.
b. Heritage: The IRAF script for performing photometry and measuring
source positions was developed for similar tests with WFPC2 and
modified for use with ACS. This is the same software to be used in the
determination of the WFC3 geometric distortion in the WF32 SMOV
program. A script will be written to take the output from this software,
and create a map of the sensitivity across the detector.
c. Platforms/systems ready to support (primary and redundant): Linux
workstation “thing”, Mac laptop “alsek”
d. Pre-launch test plan: Tables of synthetic data will be used to test the
final fitting script.
e. Test datasets (including location within /grp/hst/wfc3/):
/grp/hst/wfc3/hilbert/IRLflat_test/
7. Expected products (ISR, reference files, etc...) ?
a. Calibration reference files: Low-order flat image files will be produced
for use in calibrations.
b. Synphot data: none
c. Other CDBS data: none
d. Instrument Science Report Provisional Title:
WFC3 SMOV4 Testing: IR Low Frequency Flats