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Hubble Space Telescope
FOC Instrument Science Report #079

FOC Instrument Science Report #079

"FOC Optical Distortion Including COSTAR"
by P.E. Hodge

Abstract excerpted from the report:

This report describes the calculation of the optical distortion
of the FOC including COSTAR, based on ray tracing. Observations of 47
Tuc at different roll angles demonstrate that the pipeline calibration
file for the f/96 relay does in fact remove most of the distortion. A	
procedure for creating geometric correction reference files, combining
optical and detector distortions, is also described in detail. Poly-
nomial fits that model the optical distortion for each relay have
been installed in the 'focgeom' package directory.