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quatrope / astroalign

A tool to align astronomical images based on asterism matching
MIT License
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find_transform does not align the stars correctly #53

Closed davidenitti closed 3 years ago

davidenitti commented 4 years ago

I'm testing find_transform and it aligns the stars but often there is a misalignment of few pixels. What can I do to improve the result? an example of the difference of 2 aligned images. it should be black but you see double dots that are not aligned stars Screenshot from 2020-08-31 19-12-53

martinberoiz commented 4 years ago

That seems quite off-mark. First thing that comes to mind, is this a large field of view? In large FOV there could be non-linear distortions.

davidenitti commented 4 years ago

yes, it's a large FOV, any way to fit with such distortions?

martinberoiz commented 4 years ago

If they are truly non-linear, you can try with reproject or MontagePy, they deal with non-linear distortions. But for both you need to know WCS of both images.

martinberoiz commented 3 years ago

I will close this issue. Let me know if problem arise again.