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Hubble Space Telescope
FOC Instrument Science Report #092

FOC Instrument Science Report #092
							18 April 1996
"FOC Objective Prisms: Calibrations and Software"
by W. Hack

Abstract excerpted from the report:

A new set of F/96 near-UV (NUVOP) and far-UV (FUVOP) dispersion
curves have been derived based on Cycle 4 calibration
observations of an emission line source and a
spectrophotometric standard. These dispersion curves provide
photometry with errors of approximately 0.1 magnitudes from
1600-4000 Angstroms for the NUVOP and 1200-3000 Angstroms for
the FUVOP. Furthermore, the dispersion curves have rms errors
in the fit of 3.4 pixels for the NUVOP and 0.87 pixels for the
FUVOP. These errors in the fit correspond to errors in
wavelength determination of 1.8A at 1600 Angstroms and 17
Angstroms at 2500 Angstroms with the NUVOP and 1.3 Angstroms at
1200 Angstroms and 16 Angstroms at 1800 Angstroms in the
FUVOP. In addition to improved calibrations, the tech-niques
and software for reducing objective prism data (and used in
producing the disper-sion curves) are outlined using the
calibration observations as an example. As a result, observers
should be able to follow the procedures described here and use
the dispersion curves provided to reduce objective prism data.