 body's orientation at `et'.
 
               The following values of `abcorr' apply to the
               &quot;reception&quot; case in which photons depart from the
               target's location at the light-time corrected epoch
               et-lt and *arrive* at the observer's location at
               `et':
 
                  &quot;LT&quot;       Correct for one-way light time (also
                             called &quot;planetary aberration&quot;) using a
                             Newtonia