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FOV information from the data in the FITS header

Posted: Mon Oct 28, 2024 9:25 am
by carlomuccini
Hi

If I click in TOOLS/PLATE SOLVE (Solve only) I get information about the image in the green bar.

for example

Solution : RA=12:26:09,5,Dec=+12:56:31 (J2000)
Field of View : 1,6693x1,1367 degrees
Time : Mon, 28 Oct 2024 09:15:08 GMT
Orientation : up is 92,5 degrees E of N

I understand that the calculated FOV is not saved in the header of the FIT file or am I wrong?

Is it possible to get the FOV information from the data in the FITS header?
I found the keys "FOCALLEN" and "XPIXSZ", "YPIXSZ" but nothing about the physical dimensions of the camera sensor (which are known to the program).

Is it possible to save it in the header when saving the FITS file ?

Thank you

Carlo

Re: FOV information from the data in the FITS header

Posted: Mon Oct 28, 2024 2:32 pm
by admin
Hi Carlo,

the XPIXSZ and YPIXSZ are the dimensions of an individual pixel in microns. If you multiply those by the image resolution (width by height, in pixels), you can calculate the physical size of the sensor (or at least the area of the sensor used for the image - might be different in the case of ROI). That physical sensor size can then be combined with the focal length to give the field of view using the normal equations for FOV.

Hope this helps,

Robin

Re: FOV information from the data in the FITS header

Posted: Mon Oct 28, 2024 3:11 pm
by carlomuccini
thank you so much!

Carlo