May 2003 - first flat field - no ghost correction
Aug 2003 - Ghost Corrected - GIS 1, 150-160 ghosts, GIS 4, 760-770 ghosts 
           removed artifacts due to stim data.
Sep 2003 - Corrected wavecals for gsets 50, 73 and 76
Oct 2004 - Recalculated based on results of GIMCPS1 engineering studies. 
           Errors down from 30% to 2-5%