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Image name: Al.1_straylight_grills.png (click image to enlarge)
Image size: 161.630 KB (512x512)
Date submitted: 10-Nov-1995
L. Acton 10-Nov-95 STRAYLIGHT GRILL PATTERN IN THIN ALUMINUM There is a pattern of evenly spaced lines running from SE to NW in the Al.1 images that is more pronounced now that the straylight intensity has increased. I've had a look to see if this pattern is fixed on the CCD in the hope of improving the SFCs for Al.1 to remove it. The figure shows the result of this analysis and confirms that the pattern is stable. This figure was prepared by straylight and dark correcting 44 Al.1 FFis obtained during the first week of November '95. These 44 images were then summed without any aspect correction and FFT filtered to bring out the grill pattern (Ignore artifacts of the FFT filter process.) The fact that the grill stands out sharply in this 44 exposure sum establishes that it was stable with respect to the CCD over this period. This conclusion is bolstered by simply watching the movie of these images -- the pattern does not appear to move. The other grill pattern that runs from NE to SW in the Al.1 images does not seem to be stable on the CCD.