Keyword |
Read |
Write |
WCSAXESa |
Ignored. |
Set to the number of axes in the WCS
Frame - only written if different to NAXIS. |
CRVALia |
Used to create the pixel to WCS
Mapping. |
Always written (see ``Choice of Reference
Point'' below). |
CRPIXja |
Used to create the pixel to WCS Mapping. |
Always
written (see ``Choice of Reference Point'' below). |
CDELTia |
Used to create the pixel to WCS Mapping. |
Only
written if the CDMatrix attribute of the FitsChan is
set to zero. |
CROTAi |
Used to create the pixel to WCS Mapping. |
Only
written in FITS-AIPS and FITS-AIPS++ encodings. |
CTYPEia |
Used to choose the class and attributes of the
WCS Frame, and to create the pixel to WCS Mapping (note, ``STOKES'' and
``COMPLEX'' axes are treated as unknown linear axes). |
Always written
(see ``Use and Choice of CTYPE keywords'' below). |
CUNITia |
Used to set the Units attributes
of the WCS Frame. |
Only written if the Units attribute of the WCS Frame
has been set explicitly. If so, the Units value for each axis is used as
the CUNIT value. |
PCi_ja |
Used to create the pixel to WCS
Mapping. |
Only written if the CDMatrix attribute of the FitsChan is set to
zero. |
CDi_ja |
Used to create the pixel to WCS
Mapping. |
Only written if the CDMatrix attribute of the FitsChan is set to
a non-zero value. |
PVi_ma |
Ignored for linear axes. |
Not written if the axes
are linear. |
PSi_ma |
Ignored. |
Not used. |
WCSNAMEa |
Used to set the Domain attribute
of the WCS Frame. |
Only written if the Domain attribute of the WCS Frame
has been set explicitly. If so, the Domain value is used as the WCSNAME
value. |
CRDERia |
Ignored. |
Not used. |
CSYERia |
Ignored. |
Not used. |