s to supply to indicate the observer is 
               Earth. 
 </PRE>
<h4><a name="Detailed_Output">Detailed_Output</a></h4>
<PRE>
 
   ptarg       is a Cartesian 3-vector representing the position of 
               the target body relative to the specified observer. 
               `ptarg' is corrected for the specified aberrations, and 
               is expressed with respect to the reference frame 
               specified by `ref'.  The three components of `ptarg' 
               represent the x-, y