finding shifts for input into PyDrizzle

jlconnelly wrote on Sep 12, 2006

I am working with a large amount of STIS FUV & NUV MAMA detector data of dithered, crowded fields taken over a long period of time. Errors in the guide star positioning make it necessary to determine more refined shifts for image alignment. Unfortunately, the tweakshifts task has not produced good results. What is the best method for finding shifts given a crowded field and large dataset?

Clear Skies,
Jen

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Mike Fitzpatrick wrote on Sep 12, 2006

You might try the XREGISTER task to cross-correlate the images and get a shifts file. For crowded images you can specify various less-crowded regions in which to find the shifts, note you might still need to reformat that output to something you could use. Hope this helps.

Cheers,
-Mike

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jlconnelly wrote on Sep 12, 2006

I am actually working with images of the center of a globular cluster. I tried XREGISTER but no matter what areas of the reference image I use, it is unable to properly cross correlate the stars. Any other thoughts?

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Last post on Sep 12, 2006