Fits header WCS roll information missing

Is it possible to add the WCS rotation information to the fits header? I’m using software that uses the WCS information and am finding the CROTA2 information missing in the header. Specifically, it would be nice to see:

  • CDELT1 = -0.000666667 / Degrees/pixel
  • CDELT2 = 0.000666667 / Degrees/pixel
  • CROTA2 = 0.00000 / Rotation in degrees.

Here’s a link to the description:


Without this information, third party software can’t extract the coordinates since it’s not in standard form. An additional plate solve is required. I would think it would be easy to insert these keywords into the header.