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SUMMARY: fields | routine DETAILS: routine | ||||||||||
./toolbox decode_veldef.pro
DECODE_VELDEF |
function DECODE_VELDEF(veldef, velocity_definition, reference_frame) |
Parse the SDFITS VELDEF value into its two components, the velocity definition and velocity reference frame.
This value must contain 8 characters where the first 4 characters describe the velocity definition and the last 4 characters describe the reference frame. If the first 4 characters are recognized, they are expanded to be used in other toolbox functions (e.g. velocity_axis). Recognized velocity definitions and their expanded form are: RADI (RADIO), OPTI (OPTICAL), and RELA (TRUE). Any leading dash is removed from the last 4 characters before that value is set. In addition, OBS is translated to TOPO for topocentric. The return value is 0 if there were problems (non-standard velocity definition, wrong number of characters, etc) and 1 if everything appears to be okay.