y light time
               and stellar aberration.  See the discussion in the
               Particulars section for recommendations on how to choose
               aberration corrections.
                 
               `abcorr' may be any of the following: 
 
                  &quot;NONE&quot;     Apply no correction.  Use the geometric
                             positions of the Sun and target body
                             relative to the observer; evaluate the
                             target