|Documentation > SXT Observation Notes > this page|
Image name: Third_ent_filt_failure.png (click image to enlarge)
Image size: 4.57300 KB (512x512)
Date submitted: 28-Aug-1996
28-Aug-96 L. Acton The Third Step-Increase in SXT Visible Straylight This plot illustrates the approximate 50% increase in SXT straylight that occurred around 25 August 1996. It was made from the QR SLD exposures taken in the standard FFI table. The data have been processed as follows: 1. Read the QR ND/Open, DPE=2 data from the /yd3/temporary directory. 2. Run dark-sub on these data (note: The MSU SDC data base only goes to 96_12 so the dark frames are a bit obsolete). 3. Throw out 5 images taken after sunset. (Hmm, these would have been good dark frames.) There are 37 images remaining. 4. Sum the signal in [*,64:207], the portion of the frames which all had data. 5. Multiply the signals of the 19 "low state" sld's by 2. 6. Plot the data. We have clearly lost some more entrance filter. This calls for the following actions: a. Strong effort should be made to collect baseline terminators for this new straylight condition. b. Determine the actual time of the failure as accurately as possible. c. The "leak sub" software must be updated to select the correct straylight correction images -- based upon the time of the failure.