Changes between Initial Version and Version 1 of GPC1_Defects

Timestamp:

May 11, 2011, 3:40:16 PM (15 years ago)

Author:

eugene

Comment:

--

GPC1_Defects

@@ +1 @@
+== GPC1 Defects == 
+
+Here is an example of a small (nearly single pixel) type of defect which appears in GPC1 images but is not in our masking.
+
+The two images are a y-band TTI image pair taken 10s of minutes apart with nearly, but not quite, the same pointing.  The chip-pixel coordinates for stars differ by about 3 pixels.  
+
+The images show 3 'objects' in a triangle, and another faint object with somewhat fuzzier, larger shape.  The last object is a real PSF, and like other stars has the same celestial coordinates between the two images to 1 pixel, but chip coordinates are off by 3 pixels.  The other three objects are some kind of defect: they have the same chip pixels coordinates to better than a pixel, but differ on the sky by 3 pixels.  
+