FWHM calculation in batch mode

nice2bme wrote on Jan 17, 2007

Hi,

I have a question regarding calculating the FWHM for a list of images. I would like to automate the process without having any interaction through the display. Is there a method to do this.

I attempted doing this with the 'IMEXAM' routine provided by iraf but have not been successful. Has someone attempted this same task and succeeded, kindly help me out with this problem.

Ciao
Abhi

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Mike Fitzpatrick wrote on Jan 17, 2007

Which IMEXAM command are you trying to use? Most of the functions have task equivalents elsewhere in the system, e.g. the 'r' key and RADPROF task, the 'a' key and the APPHOT package tasks. If you have a specific list of stars you'll either want a task that takes a coord file, or if there is something peculiar to IMEXAM you can use these to create a cursor coordinate file to drive IMEXAM automatically (i.e. set the 'imagecur' param to the name of a file containing "<x> <y> <wcs> <keystroke>" one per line, see "help cursors" for details). Other tasks like STARFIND will detect all objects in an image and similarly report a FWHM for each.

Hope this helps, if you still have questions please post back.

Cheers,
-Mike

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nice2bme wrote on Jan 17, 2007

Hey Mike,

My question was specific to the apphot package. I have a list of images which contain 3 stars per image. I also have the coordinates for each star in the image. I was wondering if there was some method to use the .coo files and recover the fwhm for each star during the procedure of phot that would please my guide :wink: .

I havent figured out how to use the imexam method using the imcur file, I tried and failed miserably.

Thanks for the help, its very much appreciated. I'm trying to graduate and my advisor is not making it easy :roll:

Thanks
Abhi

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Mike Fitzpatrick wrote on Jan 17, 2007

Some quick comments: If you have the coords of the stars in one image then the IMLINTRAN is usually used to tranform the coords assuming there are shifts in other images. The doc "A User's Guide to the APPHOT package" (http://iraf.net/irafdocs/apuser/) has some notes on how to run things in batch mode, setup coords files, etc. This also discusses setting up cursor files to drive the reduction, and you might try using the 'Forum Search' banner bar to search for similar queries.

Hope this helps.
-Mike

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Last post on Jan 17, 2007