 observer's velocity, relative to the
   solar system barycenter, yields a velocity vector that points in
   the direction of the light time corrected position of the target.

   One may object to using the term &quot;observer&quot; in the transmission
   case, in which radiation is emitted from the observer's location.
   The terminology was retained for consistency with earlier
   documentation.

   Below, we indicate the aberration corrections to use for some
   common applications:

      1) Find the ap