ion below for details. 
 </PRE>
<h4><a name="Particulars">Particulars</a></h4>
<PRE>
 
   It is often convenient to describe the motion of an object in the 
   planetographic coordinate system.  However, when performing 
   vector computations it's hard to beat rectangular coordinates. 
 
   To transform states given with respect to planetographic 
   coordinates to states with respect to rectangular coordinates, 
   one makes use of the Jacobian of the transformation between the 
   two systems. 
 
   Give