I'm working with some NEOWISE images that seem to have incomplete header tags. I've been advised by the SAO (because I'm using DS9 to view them) that I have
"a partial PC matrix defined, yet it does not conform to the FITS WCS standard. With a combo of CDELT and PC keywords, the CDELT keywords hold the scaling factor, the PC keywords, the rotation matrix, which should be normalized. If you want the rotation matrix to also contain the scale factor, use CD keywords".
Here's one of the headers I need to fix:
SIMPLE = T / conforms to FITS standard BITPIX = -32 / array data type NAXIS = 2 / number of array dimensions NAXIS1 = 1459 NAXIS2 = 903 WCSAXES = 2 / Number of coordinate axes CRPIX1 = 729.5 / Reference pixel for axis 1 CRPIX2 = 451.5 / Reference pixel for axis 2 PC1_1 = -0.0333333333333 / Coordinate transformation matrix element PC2_2 = 0.0333333333333 / Coordinate transformation matrix element CDELT1 = 1. / [deg] Coordinate increment at reference point CDELT2 = 1. / [deg] Coordinate increment at reference point CUNIT1 = 'deg ' / Units of coordinate increment and value CUNIT2 = 'deg ' / Units of coordinate increment and value CTYPE1 = 'GLON-AIT' / Projection for axis1 CTYPE2 = 'GLAT-AIT' / Projection for axis1 CRVAL1 = 0. / [deg] Coordinate value at reference point CRVAL2 = 0. / [deg] Coordinate value at reference point LONPOLE = 0. / [deg] Native longitude of celestial pole LATPOLE = 90. / [deg] Native latitude of celestial pole RADESYS = 'ICRS ' / Equatorial coordinate system BAND = 'W1 ' / Wise Band END
I've already managed to fix a couple of the invalid tags, but apart from these minor edits, this is unaltered from the file that my research supervisor gave me. The FITS standard here gives descriptions of each of the tags, but I'm not sure how to implement the SAO's advice. Can anyone help me fix the tags?