The value is accessed as a position in the spectral system specified by the System attribute, but is stored internally as topocentric frequency. Thus, if the System attribute of the DSBSpecFrame is set to "VRAD", the Unit attribute set to "m/s" and the StdOfRest attribute set to "LSRK", then values for the DSBCentre attribute should be supplied as radio velocity in units of "m/s" relative to the kinematic LSR (alternative units may be used by appending a suitable units string to the end of the value). This value is then converted to topocentric frequency and stored. If (say) the Unit attribute is subsequently changed to "km/s" before retrieving the current value of the DSBCentre attribute, the stored topocentric frequency will be converted back to LSRK radio velocity, this time in units of "km/s", before being returned.
The default value for this attribute is 30 GHz.
KAPPA --- Kernel Application Package