Primary Header¶
The PRIMARY header of HST data contains keywords specifying information general to the entire file, such as what calibration steps were applied and what reference files should be used. No active WCS keywords (keywords interpreted for coordinate transformations) are present in the PRIMARY header, but keywords specifying the applicable distortion reference files can be found in the PRIMARY header. Some keywords describing the distortion model and when the WCS was updated with the distortion information from the reference files can also be found in the PRIMARY header. These distortion and WCS related keywords from the PRIMARY header are:
/ CALIBRATION REFERENCE FILES
IDCTAB = 'jref$v8q1444sj_idc.fits' / image distortion correction table
DGEOFILE= 'jref$qbu16420j_dxy.fits' / Distortion correction image
D2IMFILE= 'jref$v971826mj_d2i.fits' / Column Correction Reference File
NPOLFILE= 'jref$v971826aj_npl.fits' / Non-polynomial Offsets Reference File
UPWCSVER= '1.0.0 ' / Version of STWCS used to updated the WCS
PYWCSVER= '1.11-4.10' / Version of PYWCS used to updated the WCS
DISTNAME= 'jbf401p8q_v8q1444sj-v971826aj-v971826mj'
SIPNAME = 'jbf401p8q_v8q1444sj'
The remainder of the PRIMARY header specifies the general characteristics of the image.