Re: Align stack using WCS or apertures problem

Posted by karenacollins on Nov 01, 2017; 10:15am
URL: http://astroimagej.170.s1.nabble.com/Align-stack-using-WCS-or-apertures-problem-tp722p889.html

Hi asteroidguy,

Partial pixel photometry was added since 3.2.0 and is the default. The routine is much more complex and could be slowing the alignment of small images down. Also, partial pixel photometry probably will not improve alignment, so could you try disabling that option in the aperture settings panel and let me know if that makes the difference? If it does, I'll consider overriding the setting when stack aligner is running so that it doesn't have to be manually disabled.

The AIJ alignment routine actually crops images as necessary to align them with the first image of a stack, rather than adding extra columns or rows. Is there any chance this is what is going on when you mentioned they are not aligning? I'm not sure why there would be a difference in the alignment between the two AIJ versions. Can you confirm that you tried aligning the same stack with both AIJ versions and got a different result? Also, are you aligning using a virtual stack? If so, you have to reopen the stack from the "aligned" subfolder to see the aligned images.

If none of the above addresses the issues, I might need to work out a way for you to send me an example datacube that displays this problem so I can test and debug here locally.

Karen