Instrument Science Report CAL/FOS-152 (97-02)

Location of FOS Spectra: Cycles 5 and 6

Ed Smith, Anuradha Koratkar, Steve Martin and Michael Dahlem

July 14, 1997

Abstract:

The optimal locations of the FOS spectra were determined and the
Project Data Base (PDB) updated accordingly on four occasions during
Cycle 5 and 6: October, 1995; January, 1996; June, 1996; and December,
1996.  The October, 1995, and January, 1996, updates included pola
rimetry positions.  These calibrations used the data from proposals
5530, 6146, 5579, 6206, 6166, 6236, 6913 and 6914.  All individual
measures and PDB updates from this time period are included in this
report.  Analysis shows the continued linear spatial drift with time
in the positions of the spectra for all gratings observed with the
FOS/BLUE detector while the locations of the spectra for all gratings
using the FOS/RED detector remained scattered.  An increase in the fre
quency of G270H measurements has provided a much clearer view of the
true scatter in FOS spectral positions.