Changes between Version 1 and Version 2 of HeathersStackingAdventures

Timestamp:

Apr 1, 2013, 1:41:09 PM (13 years ago)

Author:

heather

Comment:

--

HeathersStackingAdventures

@@ -7 +7 @@
  1. why are there big chunks missing
  2. why did it take 10k seconds?
- 3. why are the edges nan'd off
+ 3. why are the edges nan'd off (gene says convolution, so that's ok for now)
 
 These are stacks of roughly 100-200 skyprobe warps (in a special skyprobe tessalation where the pixel size is the size of a skyprobe pixel, and the 'skycell' is the size of a projection cell. The first investigation (why are there big chunks missing) I answered by writing a tool (in ipptrunk/tools/heather/stack_inspector.pl) - give it a stack_id, it will make binned fits of the stack and the input warps. You can easily open up the stack and all the inputs, which I did with skycell 1315 (g band).  What I found out is that everything is covered multiple times. The skycell should be completely filled with pixels.
 
-At this point, I committed a sin: I downloaded IRAF to see if it could stack better. I did the dumbest stack possible (I fed it 200 images and said, go make a stack). IRAF complied and gave me a stack ~ 1 minute later, completely filled, very deep, very nice:
+At this point, I committed a sin: I downloaded IRAF to see if it could stack better. I did the dumbest stack possible (I fed it 200 images and said, go make a stack), and I stacked stack_id 33. IRAF complied and gave me a stack ~ 1 minute later, completely filled, very deep, very nice. Note that the astrometry is crappy for some of the warps, and it prints through on both ipp and iraf.
 
-[[Image(stuff.png)]]
+(left IRAF right IPP)
+
+[[Image(skyprobestack.jpg)]]
 
 Next was to play with gpc1 images with IRAF for SAS. I downloaded a random g band skycell ( skycell.1495.014 ), grabbed the inputs, and stacked.  I discovered 2 things:
@@ -47 +49 @@
 Here is a comparison of IRAF to IPP for gpc1
 
-[[Image(stuff.png)]]
+(left IRAF right IPP)
 
+[[Image(sasstack.jpg)]]
+
+Now for the big question: how to make ppStack look more like IRAF?
+