Changes between Version 2 and Version 3 of staticsky.20120706_excess_detections

Timestamp:

Feb 4, 2013, 2:34:05 PM (13 years ago)

Author:

bills

Comment:

--

staticsky.20120706_excess_detections

@@ -11 +11 @@
 
 The following plot shows the number of detections per skycell as a function of RA and DEC in g and in y band.
+The region near the galactic plane is clearly visible as is M31. Note the various regions where the detection count is much
+higher than the surrounding regions. These are the skycells under discussion in this wiki page
 
 [[Image(g_detect.jpg)]]
 
 [[Image(y_detect.jpg)]]
+
+== Example y band stack 1715750 skycell.1927.074  23.1369h, 27.004d ==
+
+Stack_id 1715750 is an example that shows this problem. 55284 sources were detected in y band while < 6400 were detected
+in the stacks for the other 4 filters.
+
+The following image shows the stack with the individual detections displayed as yellow or green circles. Note that there are
+areas which fall in chip and cell gaps from one or more of the inputs do not show the enhanced detections. This indicates that
+the phenomena is likely due to a subset of the input warps
+
+[[Image(stk.1714750.jpg)]]
+
+This image shows the input warp images. Here we can see that the area with lower detection count matches the outline of the
+fourth and fifth images. Since the fourth image was rejected it looks like the excess detections come from areas where the
+fifth image contributes. This is warp_id 612302. Examining the image we find obviously unusual. 
+
+[[Image(input_warps.jpg)]]
+
+Here is a copy of the log file for the stack.