The PROS software supports Celestial, Ecliptic, Galactic and Supergalactic coordinates. However, the sky system may be changed by explicitly declaring the new system, as in the examples below. Logical, physical and world coordinate systems are all supported in the PROS software, and regions can be specified with any combination of them. When a qpoe file is displayed and no blocking or subsectioning has been applied, the physical and logical units are the same.
Input can be in any of the above syntaxes, in physical, logical and world coordinates.
If SAOimage is used to make a region file the output is in logical pixels, regardless of the input units. There is a task, fixsaoreg , which will convert these logical coordinates to physical coordinates, which free the region definition from the particular section used in SAOimage. Then a PROS task like imcnts can use the converted region file with any image or section derived from the original source image. Also, see fixsaoreg, skypix, and wcscoords for information regarding coordinate conversion.