ref="dpr_c.html">dpr_c</a>(),
                    solar  * <a href="dpr_c.html">dpr_c</a>(),
                    (long) lit,
                    emissn * <a href="dpr_c.html">dpr_c</a>(),
                    (long) visible,
                    <a href="vnorm_c.html">vnorm_c</a>( srfvec )     );

                    /.
                    Compute the illumination angles using an ellipsoidal
                    representation of the target's surface. The role of
                    this representation is to p