CTYPE inconsistency in header for data in spectroscopic mode
For dataset in spectroscopic mode, the first axis seems to be always wavelength.
But this is not consistent with the CTYPE-i keywords later.
e.g.
SIMPLE = T / conforms to FITS standard
BITPIX = 32 / array data type
NAXIS = 3 / number of array dimensions
NAXIS1 = 1010 / Length of data axis 1
NAXIS2 = 484 / Length of data axis 2
NAXIS3 = 1 / Length of data axis 3
FILENAME= 'gris_20160613_120408_l1s_008_120_0029.fits' / Name of file
EXTNAME = '20160613_008_120_0029' / Unique HDU name
POINT_ID= '20160613_008' / Unique (re-)pointing ID
OBS_TRGT= 'Sunspot(s)' / Observation Target
WCSNAME = 'Helioprojective Cartesian' / nan
CTYPE1 = 'HGLN-TAN' / Type of coordinates along axis 1
CUNIT1 = 'arcsec ' / Units along axis 1
CRPIX1 = 0 / Reference pixel
CRVAL1 = 297.671 / Value at reference pixel on axis 1
CDELT1 = 0.080792 / Sampling along axis 1
CSYER1 = 1900 / Systematic Error along axis 1
CTYPE2 = 'HGLT-TAN' / Type of coordinates along axis 2
CUNIT2 = 'arcsec ' / Units along axis 2
CRPIX2 = 0 / Reference pixel
CRVAL2 = 408.258 / Value at reference pixel on axis 2
CDELT2 = 0.080792 / Sampling along axis 2
CSYER2 = 1900 / Systematic Error along axis 2
CTYPE3 = 'WAVE ' / Type of coordinates along axis 3
CUNIT3 = 'Angstrom' / Units along axis 3
CRPIX3 = 0 / Reference pixel
CRVAL3 = 10823.076 / Value at reference pixel on axis 3
CDELT3 = 0.017998 / Sampling along axis 3
CSYER3 = 0.017998 / Systematic Error along axis 3