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LSSTDESC / descwl-coadd-task

DM Task to run coaddition in cells
BSD 3-Clause "New" or "Revised" License
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Add PSF warping #8

Open esheldon opened 4 months ago

esheldon commented 4 months ago

Add psf warping to MakeShearWarpTask.run

esheldon commented 4 months ago

https://github.com/LSSTDESC/descwl_coadd/blob/cb1f30c93387bf214476c50cef2a79ce27117daa/descwl_coadd/coadd.py#L627

https://github.com/LSSTDESC/descwl_coadd/blob/cb1f30c93387bf214476c50cef2a79ce27117daa/descwl_coadd/coadd.py#L248

arunkannawadi commented 4 months ago

Invalid issue. PSF does not get warped in Warping task.

esheldon commented 4 months ago
  1. Where does it get warped?
  2. Will it use our warping code to prevent biases?
  3. How can we test it for consistency with the image warps? This is also needed to prevent bias.
arunkannawadi commented 4 months ago
  1. It gets warped during the coaddition stage. This is why I had to refactor out the PSF warping in the first place.
  2. It uses warp_psf method.
  3. One way would be to paste the PSF image in the calexp with the appropriate sub-pixel offset as some kind of a noiseless star and see that that is consistent with the PSF image on the coadd.
arunkannawadi commented 4 months ago
  1. Now that I look at it, it delegates all of that to make_coadd function from descwl_coadd.

https://github.com/LSSTDESC/descwl-coadd-task/blob/main/descwl_coadd_task/_coadd_task.py#L451-L462

esheldon commented 4 months ago

OK, in that case we can test it when we add a test_coadds.py