WCS Coordinates with IRAF
AnTaR3s wrote on May 07, 2010
Hi
I have a little problem with a WCS calculation in IRAF. What I have are images without any information on RA/Dec Coordinates, so I used the ccmap utility within images.imcoords package. There I can define some 'standard' stars with given pixel and WCS Coordinates and calculate the coordinate system with ccmap and ccsetwcs. I succeeded in doing so and the WCS system is displayed correctly, but only when I open the images outside of IRAF. When I open the images with IRAF (i.e. display imagename frame) the WCS system does not appear in DS9.
Any suggestions on how to solve that problem?
thanks
cheers ;)
I have a little problem with a WCS calculation in IRAF. What I have are images without any information on RA/Dec Coordinates, so I used the ccmap utility within images.imcoords package. There I can define some 'standard' stars with given pixel and WCS Coordinates and calculate the coordinate system with ccmap and ccsetwcs. I succeeded in doing so and the WCS system is displayed correctly, but only when I open the images outside of IRAF. When I open the images with IRAF (i.e. display imagename frame) the WCS system does not appear in DS9.
Any suggestions on how to solve that problem?
thanks
cheers ;)
Mike Fitzpatrick wrote on May 07, 2010
This is a long-standing problem with DS9 in that it doesn't make use of the file information sent in the display to open the image to read the WCS or pixel values. The only workaround is to use the File->Load menu item to have DS9 load the image directly or use another server like XImtool.
AnTaR3s wrote on May 07, 2010
Thanks once again for your help
I guess this won't compromise my future reductions... ;)
I found that IRAF can display a coordinate grid with the wcslab-tool in the tv package, but unfortunately that's not nearly as useful as a complete support would be. ;)
I guess this won't compromise my future reductions... ;)
I found that IRAF can display a coordinate grid with the wcslab-tool in the tv package, but unfortunately that's not nearly as useful as a complete support would be. ;)
newirafuser3 wrote on May 07, 2010
Hi, I didn´t want to open a new thread and I have a question related to wcs in ds9. I´ve searched around and couldn´t find an answer.
I know using display in iraf won´t show the wcs of a frame. I open the files manually in ds9. The problem is that the RA and Dec values in my wcs for each frame are out of bounds. I have the latest version of ds9 and Ive tried quite a few frames and none have their wcs set properly. What can I do?
Thanks
Pete.
I know using display in iraf won´t show the wcs of a frame. I open the files manually in ds9. The problem is that the RA and Dec values in my wcs for each frame are out of bounds. I have the latest version of ds9 and Ive tried quite a few frames and none have their wcs set properly. What can I do?
Thanks
Pete.
Mike Fitzpatrick wrote on May 07, 2010
A definitive answer would have to come from the authors at SAO, but if you post the image header here, and what values you're expecting vs what you see we might be able to spot a problem (e.g. values in hours instead of degrees, etc).
Last post on May 07, 2010