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.
