9190(  1) - 12/20/00 23:36  - [  1]

    PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS   ST ScI Use Only
                                                       ID:      9190
                                                       Version: 1
                                                       Check-in Date: 20-Dec-2000
                                                                      23:23:57

1.Proposal Title:
Calibrating the Optical Field Angle Distortions of FGS1r
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2. Proposal For  3. Cycle
AR               10
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4. Investigators
                                                                                     Contact?
    PI: G. Fritz Benedict                 University of Texas at Austin
   CoI: Ms. Barbara McArthur              University of Texas at Austin                 N
   CoI: Dr. Edmund Nelan                  Space Telescope Science Institute             N
   CoI: Prof. William Jefferys            University of Texas at Austin                 N

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5. Abstract

The analysis we propose will complete the commissioning of FGS1r as a sub-
milliarcsecond astrometric science instrument for Cycle 10 and all future HST
cycles, and permit the final reduction and analysis of ~100 orbits of FGS1r data
acquired by a variety of GO programs during HST Cycles 8 and 9. As our team consists
of members from the original astrometry Instrument Definition Team (STAT) and
STScI's FGS Instrument Scientist, we have already performed this calibration for
FGS3, and we are uniquely qualified to do so for FGS1r. Using data obtained from an
approved FGS1r Cycle 8 Calibration program (Prop 8469), we will map the optical
field angle distortions of FGS1r to facilitate the goal of millisecond of arc
precision astrometry for FGS1r's Position Mode. Our results will populate the FGS1r
calibration database and will be available to all FGS GOs through the use of STScI's
calibration pipeline. A second result will be an improved M35 calibration field, one
that takes into account proper motions in the catalog. This will allow for more
accurate monitoring of the FGS1r plate scale and distortions during future HST
cycles.
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                                                9190(  1) - 12/20/00 23:36  - [  2]

            Summary Form for Proposal  9190

  Item                         Used in this proposal
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  Proposal Category            AR
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