World Coordinate Systems in SAOimage
If WCS information is present in the image header, SAOimage
versions from 1.12 track world coordinate systems as well as pixel
coordinates within the image. Two single character keyboard commands
have been added:
- c prints the world coordinate (RA and Dec as
hh:mm:ss.sss dd:mm:ss.ss and Lat Long as dd.ddddd dd.ddddd)
and image pixel coordinate, along with the value of that pixel to standard
output.
- w executes the command set by -wcscom command_%s,
substituting that same world coordinate string for %s.
SAOimage versions from 1.14 add three more keys:
- b prints the current cursor coordinates in the B1950 (FK4) system.
- j prints the current cursor coordinates in the J2000 (FK5) system.
- g prints the current cursor position in galactic coordinates.