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wiki:ppSub_testing_201201

Version 27 (modified by Mark Huber, 14 years ago) ( diff )

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Summary of ppSub_testing_201201 ---IN PROGRESS PLEASE DO NOT EDIT---

  1. Summary of ppSub_testing_201201 ---IN PROGRESS PLEASE DO NOT EDIT---
    1. Background
  2. Setup
  3. PSF Matching/Convolution
    1. Poor PSF-matching?
    2. No-convolution?
  4. Convolution direction choice
  5. Test Sets
    1. MD04 primary samples
    2. Simulated Samples
  6. Monitoring
    1. Nightly Tests of Diffims
    2. HOTPANT Diffim Comparisons

The primary purpose has been expanded and redirected. While it appeared that the fixed convolution direction may have been the likely cause of an overabundance of false detections from residuals of bright sources in the field, issues also in the convolved stack with a resulting larger than selected target PSF has illustrated there may also be issues with the PSF matching/convolution itself. So the scope of testing has been broadened/focused to the PSF matching/convolution

  • is ppSub doing what we want
  • is ppSub doing what we think
  • has something changed in the data or what the code is doing

General tasks (no particular order):

  • wrap up test and activate the convolution direction choice in ppSub for general use option
  • test and verify the PSF matching/convolution, include the "no-conv" case as well for close matches
  • investigate options for the false detections (may be flags2 use, may be solved with PSF matching or convolution direction)
  • monitor if working as expected and address any additional issues found
  • establish a baseline to verify against any past/future changes in code and with reprocessing (a test set of real+simulated images)

Background

Samples of previous information/work/comparisons

Setup

Operations tag for testing base diffims is ipp-20111220 (since local tests could/should fix at some r since the tag has revisions added to it? )

Branch for originally testing the choice of convolution direction but now full development testing is also updated to r33098 (from 1/11/2012) -- ​http://svn.pan-starrs.ifa.hawaii.edu/trac/ipp/browser/branches/meh_branches/ppsub_test

  • for convolution direction choice
    • normalization updated each direction -- need to look if in path for ppStack fixed, seem to recall modifies even fixed
  • for both
    • kernel scaling based on

PSF Matching/Convolution

Poor PSF-matching?

Not sure yet what to classify this as other than the PSF not being matched well. Suspect similar to issue with convolved stacks in ppStack.

No-convolution?

Reports from other surveys that diffims are poorer with images having similar PSFs, convolution isn't well matched? Is this for dual only?

Convolution direction choice

We want to avoid large deconvolution in PSF-matching image subtraction. As the image quality of the images continues to improve, always convolving the reference stack will not produce the best difference image and convolving the input image is desired. The quality of the difference image is evaluated in both directions and the better is chosen for the output (need to add specific condition test).

MD04 sample:

Not all seem to be really due to convolving in the wrong direction and need to identify and separate the cases/causes if can. Running samples forced in both direction useful to see.

CfA photpipe/HOTPANTs direction: using single template/reference stack so locally get keyword CONVOL00 from header except slight issue with amps. All are convolving the TEMPLATE only so also suggest issue seems not a convolution direction but convolution issue itself.

  • discovered the current photpipe setup is now set to for convolving the template only.. rather then testing both.. argh..

Sample diffims with direction forced and detections marked (note both stack-refstack and stack-stack cases). The stack-stack case is the really the only way to test the convolution direction choice now unless go back to the MD04.V2 sample. (easiest to use event stamps from pages, but may want image photpipe diffim..)

  • ref - ref
  • stk - ref vs ref - stk (both directions)
  • stk - stk (both directions)
event (auto direction) TARGET2 (convolved ref) / TARGET1 (convolved stk) photpipe automatic (direction) comment
X (TARGET2) No image "test.png" attached to ppSub_testing_201201 No image "test.png" attached to ppSub_testing_201201 (TEMPLATE) conv refstk better,

Photometry/detection comparisons:

Simulated sample:

Test Sets

Need tests to verify changes will not break diffims for other surveys (MOPS etc) but do not need to worry about magic now. Not for testing if they will choose the right direction (only if using AUTO), but changes involved part of the normalization and will need to verify doesn't change flux/variance values:

  • MD
  • simulated image set WW,WS,SS, SSref -- since SSref for MD04 seem to prefer convolving the deeper refstack still, will need to generate
  • warp-warp diffim: MD and 3PI TTI
  • warp-stack diffim: MD and LAP stack

MD04 primary samples

Initially selected for if choosing the proper direction in stack-stack diffims now using MD04. Was previously done using MD10, but we want to continue to build up a test set for testing other parts of the IPP and MD04 is a favorite with extensive overlap from other surveys.

Start with just 2 skycells having example events from last year for photometry comparisons as well -

skycell.055 (previous tessellations 077) -- near center -

skycell.058 (previous tessellations 073) -- edge -

QUB cross-match page: ​http://star.pst.qub.ac.uk/ps1/psdb/crossmatchipptocfa/ (add when time.. difficult to search the new crossmatch page..)

Difficult to use past examples of wrong convolution direction since refstacks remade, so select sample to just test current choices. The monitoring part should take care of of this in more recent cases as MD04 actively being observed for next couple months.

QUB examples of wrong convolution choice:

Sample nightly stacks for both skycells with same obsdate to look at variation of PSF center and edge (0.25 "/pixel), limited to r-band for now and a sample size that can be manually rerun with some ease.

obsdate stack_id FWHM_MAJ (pixel) IQ_FW1 (pixel)
skycell.055
refstack.20111012 450933 5.206454 (+-0.6-0.8) not the 4.5 on the MD.GR0 page.. 4.08811 (+-0.3-0.4)
20100110 444020 4.878624 3.891729
20100121 444079 5.843588 4.574009
20110129 444251 4.424473 3.378561
20110201 644876 5.746622 4.748873
20110312 446658 4.958342 3.74775
20110315 645114 4.270276 3.232871
20110423 446715 4.603964 3.510957
20110429 645474 7.178107 6.027955
20120115 622752 5.805826 4.622056
20120121 646801 6.346761 5.359003
(swap 20120126 for 20120115?) 676389 4.443175 3.475093
skycell.058
refstack.20111012 450936 4.616929 3.926292
20100110 444023 4.777016 3.687181
20100121 444082 5.567342 4.243489
20110129 444254 3.976701 3.100284
20110201 644879 5.023516 4.421264
20110312 446661 5.114515 3.701454
20110315 645117 4.58284 3.376984
20110423 446718 4.358292 3.138227
20110429 645477 6.088856 5.447231
20120115 622755 5.300241 4.337034
20120121 646804 5.627441 5.058287
(swap 20120126 for 20120115?)

Simulated Samples

Simulated image sample:

filename sim FWHM FWHM_MAJ (pixel) IQ_FW1 (pixel)

Monitoring

Nightly Tests of Diffims

Is there any conflict with the expected desired direction? Compare to CfA photpipe, detection counts.

  • having IQ/FWHM keywords in stack images or at least the gpc1 DB would be helpful here since are calculated for the PSF matching in the diffim process, doing manually here takes a good amount of time.

Is the convolution not optimal?

HOTPANT Diffim Comparisons

Difficult to automate and may want to force both directions for comparison as well as shallower reference stacks to use. Are the diffims continuing to produce similar results.

  • for select night samples should setup and run locally. still on the todo list.

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