#### Description:

This attribute is a boolean value which specifies how FITS `"` CAR`"` (plate carree, or `"` Cartesian`"` ) projections should be treated when reading a FrameSet from a foreign encoded FITS header. If zero (the default), it is assumed that the CAR projection conforms to the conventions described in the FITS world coordinate system (FITS-WCS) paper II `"` Representation of Celestial Coordinates in FITS`"` by M. Calabretta & E.W. Greisen. If CarLin is non-zero, then these conventions are ignored, and it is assumed that the mapping from pixel coordinates to celestial coordinates is a simple linear transformation (hence the attribute name `"` CarLin`"` ). This is appropriate for some older FITS data which claims to have a `"` CAR`"` projection, but which in fact do not conform to the conventions of the FITS-WCS paper.

The FITS-WCS paper specifies that headers which include a CAR projection represent a linear mapping from pixel coordinates to `"` native spherical coordinates`"` , NOT celestial coordinates. An extra mapping is then required from native spherical to celestial. This mapping is a 3D rotation and so the overall Mapping from pixel to celestial coordinates is NOT linear. See the FITS-WCS papers for further details.

Type:

  Integer (boolean).

#### Applicability

##### FitsChan

All FitsChans have this attribute.
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