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Is it possible to use CCMAP's output (database) as a database input for GEOTRAN?

Hello,This is not a crazy question and I've never thought of it. However, the answer is no. GEOTRAN works on the output of GEOMAP and not CCMAP. You can probably couple the two by using tasks that evaluate the CCMAP database (e.g. CCTRAN) to create the data for GEOMAP. GEOMAP would be run non-interactively followed by GEOTRAN. This kind of usage, creating a text file with a grid of points over some image and using CC tasks to produce input for GEOMAP/GEOTRAN, is common in resampling scripts like the *REGISTER tasks or MSCIMAGE.If you want to spell out more completely what you want to do I could give you advice. I am not completely clear what you want to do based on your question.Yours,
Frank Valdes

Hi Frank,thank you for the quick replay. My problem is as follows: I need to have precise astrometric information on my FITS images. For this I tried to use CCFIND, CCMAP and CCSETWCS. However, as CCSETWCS is not able to write the higher order terms that CCMAP produces into the FITS headers, I was trying to use GEOTRAN to create a resampled image on a rectified coordinate grid.Yours,
Tiina Liimets

Hi Tiina,As there is no standard for distorted WCS there are some special "projections" in IRAF to encode such information. The simplest is to set the projection to "tnx" in ccmap and update the header. I'm not completely sure if you can simply use ccsetwcs with projection="tnx" if you didn't set that in ccmap. But it looks like that might work. See the linkhttp://iraf.noao.edu/projects/ccdmosaic/tnx.htmlfor more information. You might also be interested inhttp://iraf.noao.edu/projects/ccdmosaic/astrometry/astrom.htmlThough it talks about mosaic data it applies equally well to single image data. I would also mention the task mscred.mscfinder.msctpeak (msctpeak in the mscfinder subpackage of the mscred external package). With an image display it is particularly useful for setting up WCS (again using tnx as the projection type).Once you have a tnx project (e.g. FITS keyword CTYPEn=xxxx-TNX) you can use ds9 or wcsctran or other IRAF tools to convert pixels to RA/DEC and vice-versa. Note TNX is not a FITS standard but DS9, XIMTOOL, and IRAF are all aware of this WCS. There is no need to resample for getting coordinates though you are free to do that with mscred.mscimage (which is one of those tasks that combines WCS and GEOTRAN). Resampling is normally used only when you need to stack images on a common WCS.Frank

Hello Frank,it works! I set TNX in CCMAP and then CCSETWCS is doing the rest of the job concerning the fits header. Thank you very much you have saved my theses or at least fastened my way towards the end. Yours,
Tiina