  This works presents a program which computes velocities of an Earth-bound
observatory in the reference frame of the barycenter of the solar system. It
feeds from ephemerides files of the Jet Propulsion Laboratory to extract the
velocity of the geocenter, optionally with corrections from Earth rotation data
of the International Earth Rotation Service, takes a datum (time and geodetic
location) of the observer as parameters, and processes these data with the
program library of the working group `Standards of Fundamental Astronomy' of
the International Astronomical Union.
  The prospective application of the computed velocities is to subtract their
projection onto a pointing direction from observed velocities in a step of data
reduction of astronomic radial velocities.
