Apall routine problem

adamclarke wrote on Jan 30, 2011

Hey

Having a problem using the apall routine as outlined in the IRAF guides. When I read in an image and go on to define apertures, the routine seems to be plotting a spectra rather than a pixel count in the y direction.

Basically it looks to me that the x and y axis are backwards to what IRAF expects them to be. And without it being the right way, It cant extract the spectra.

Any suggestions on how to fix this would be really good. Seems odd that IRAF defaults to having dispersion vertical on the ccd and spacial dispersion on the horizontal plane. I thought most CCD's were the other way around as is mine.

Thanks a bunch.
Adam

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Mike Fitzpatrick wrote on Jan 30, 2011

Do an "epar apextract" and reset the 'dispaxis' parameter. This is what allows the dispersion to run in either direction, it sounds like the default is just different from what you need.

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adamclarke wrote on Jan 30, 2011

Thank you =] I'll give this a go tomorrow.

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adamclarke wrote on Jan 30, 2011

This worked fine Thanks.

Another issue now is that i save the aperture details for use on the next ccd image.
Then do:

$ apall a2600265.fits ref=database/apa2600263

And i get an error saying that Refernce apertures cannot be found. I'm following a guide. So I dont think its something I have done wrong. Its definitely written the file from the previous CCD image to database/apa2600263

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Mike Fitzpatrick wrote on Jan 30, 2011

I think what you want to do is set the 'reference' parameter to be the name of the image who's solution you want to use, not the name of the database entry.

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adamclarke wrote on Jan 30, 2011

Aha. I understand, ill try that and let you know.

Thanks for the speedy response again =]

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Last post on Jan 30, 2011