World Coordinate System


The term "World Coordinate System", or "WCS" refers to a coordinate system that describes the positions of objects in the sky rather than in the columns and rows of an image. Mira adopts the WCS definition of the FITS format standard. This standard proscribes a specific way in which both world coordinates are to be expressed in the image header and also the image coordinate system details for a FITS format image. Any FITS image meeting the FITS WCS standard will be properly interpreted by Mira.      

For images containing WCS information, Mira shows image coordinates, measurements, and plots in either WCS units or the native array system of (column,row). For WCS calibrated images, you can select which plot coordinate system to use.

Note

Mira implements FITS WCS support using the dynamic link library FitsWcs.dll. This library resides in the Modules\ subdirectory. If this DLL is not present at startup, Mira will run normally but will not display world coordinates for FITS images even though they contain WCS information.

Related Topics

Image Coordinate System, Plot Coordinate Systems, Image Coordinate Readout, Point Measurements, Image Window

Set Equatorial WCS, Set Arcsecond Scale