 surface. 
                    ./
                    <a href="subpt_pl02.html">subpt_pl02</a> ( handle, &amp;dladsc, method, 
                                 target, et,      abcorr, 
                                 obsrvr, xpt,     &amp;alt,   &amp;plid );

                    /.
                    Compute the illumination angles at the sub-observer
                    point. Also compute the light-of-sight visibility and
                    shadowing flags.
                    ./
                    <