imalign question

santiago wrote on Oct 08, 2009

Hi, i'm trying to align several tenths of images and i tried to do this, first ran daofind to detect stars on each image. With this i suppose that most of the stars detected appears in all images, some not. In each coord file the same stars would have little differences in coordinates, say no more than 50 - 80 pixels... is there any way to IRAF to look for coorelation between all these coords files and do some star matching? i tried with the task imalign but some warnings appear saying "fail to converge near (1602,1)" for example... and then says "Problem with coarse centering" and then other line "no shifts were calculated".. any suggestion? I ran daofind with high threshold in order to avoid detecting like thousand of stars... currently i'm detecting ~850 stars on each frame... my goal is to get those images aligned ... and first runs of imalign with default box sizes completed triming and shifting but the align was wrong and blinking images showed no improve in alignment.

Regards,

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santiago wrote on Oct 08, 2009

i was looking around many tasks and i see that "rimcursor" allow me to get (x,y) of cursor when y hit space... but this is pixel coordinates, no centroid calculation is done... is there any task or a adequate combination of ones that do the same task of "rimcursor" but with some centroid calculation? May be with the same stars, a few per frame i can try to perform imalign, or trying to establish a coordinate coorelation in order to get frames aligned.

thanks for any help,

Santiago.-

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Last post on Oct 08, 2009