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Hubble Space Telescope
FOC Instrument Science Report #085

FOC Instrument Science Report #085
							15 Jan 1996
"Results of the Cycle 4 FOC DQE Program"
by R. Jedrzejewski

Abstract excerpted from the report:

This report describes the calibration of the FOC+COSTAR DQE from
in-orbit data. Two spectrophotometric standard stars were observed
through many FOC filters to determine the absolute sensitivity. The
data were analyzed in a significantly different fashion from earlier
(pre-COSTAR) data, largely because of the smaller field of view of
the COSTAR-corrected FOC. It was found that the (Observed/Expected)
fluxes followed a linear relation with wavelength, and when the FOC 
DQE curve was corrected by this function, r.m.s. residual errors
of only 6% in the absolute flux determination remained. Analysis of
the ND filter transmissions did not show any significant differences
between the observed and expected throughputs, although more work is
needed to check this finding. The Pseudo-Strehl and FWHM performance
characteristics of the FOC were measures and plotted to assist 
potential users, and a comparison of FOC and WFPC2 sensitivities in
the ultraviolet shows that the FOC is significantly more sensitive
for all wavelengths below 4000 Angstroms.