search

c3-time-domain / SeeChange

A time-domain data reduction pipeline (e.g., for handling images->lightcurves) for surveys like DECam and LS4
BSD 3-Clause "New" or "Revised" License
0 stars 4 forks source link

Check images overlap when aligning #196

Open guynir42 opened 8 months ago

guynir42 commented 8 months ago

Each image needs to overlap the target image by X percent (which is a parameter that you can define). If it doesn't overlap enough, should raise an exception and not let you do the coadd.

guynir42 commented 6 months ago

could be a good second issue or third issue.

guynir42 commented 3 months ago

Actually, now that I think about this, it could be a really useful thing for References, too.

guynir42 commented 3 months ago

Could use someone who's already familiar with the Shapely module... @dryczanowski

rknop commented 2 days ago

This is implicitly done already with code in the reference building refactor.

Right now, zogy and naive coaddition methods sort of implicitly assume that there is a lot of overlap. For those, perhaps this issue would be relevant, and the fraction should be pretty high until we relax that condition.

For swarp, it does a scamp to match sources on each image in the coadd with the target image. If the scamp fails, then the coadd will fail. This will require at least enough overlap so that scamp is able to get a reasonable mapping of coordinates from the to-be-coadded image to the target, which is what we really want when coadding together a bunch of images that may not all be aligned with each other.