apall command shifting the aperture
Sherry wrote on Feb 14, 2012
IRAF is giving me apall centers that are shifted by ~200 channels.
This is only happening with asteroid spectra as apall is reading out the correct cenrtwertd for bstandard star spectra. What is going on?
linux 64 bit iraf v2.15.1a
This is only happening with asteroid spectra as apall is reading out the correct cenrtwertd for bstandard star spectra. What is going on?
linux 64 bit iraf v2.15.1a
Francisco Valdes wrote on Feb 14, 2012
Hello,
I need some more information to try and understand this. It is not clear if you are finding the defined apertures are off or that the extractions are off. Could you send a long image header listing of the image. In particular, I suspect it has something to do with using data which was previously extracted as a subsection of another image. This would be apparent in the presence of keywords LTVi/LTMi_j. If that is it then there is an easy solution to remove these or use the task "wcsreset". Other useful information are parameter listings and the database file. While I can can generate a test file from a header listing if I need something to actual see where you are trying to define apertures I might need the image data. But for now just send the header listing.
Yours,
Frank Valdes
I need some more information to try and understand this. It is not clear if you are finding the defined apertures are off or that the extractions are off. Could you send a long image header listing of the image. In particular, I suspect it has something to do with using data which was previously extracted as a subsection of another image. This would be apparent in the presence of keywords LTVi/LTMi_j. If that is it then there is an easy solution to remove these or use the task "wcsreset". Other useful information are parameter listings and the database file. While I can can generate a test file from a header listing if I need something to actual see where you are trying to define apertures I might need the image data. But for now just send the header listing.
Yours,
Frank Valdes
Last post on Feb 14, 2012