./toolbox
decode_veldef.pro

Last modification date:

Wed Sep 28 13:27:10 2016

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.

Returns

1 on success and 0 on failure.

Version

$Id$

Copyright

NRAO

Parameters
veldef in, required string	The value to decode.
velocity_definition out, required variable	. This will be one of the standard types, RADIO, OPTICAL, or TRUE, or a copy of the first 4 characters (if the latter, the return value will be 0).
reference_frame out, required variable	. This will be the last 4 characters minus any leading dash.