The task uvlist
can be used to list information about the
frequency and velocity setup, with the options=spectral listing.
This prints out the velocities for a visibility record. It is suggested that
you do this before proceeding much further, to ensure that the velocity
and rest frequency information is what you expect.
The task varplt
can be used to plot or list the observatory's
radial velocity as a function of time. Use the parameter setting
yaxis=veldop.