 target, 'SUN',  et,  fixref, ...
                                           abcorr,  obsrvr,  ssolpt );

            %
            % Do the same for the sub-spacecraft point.
            %
            [ trgepc, srfvec, sscphs, sscsol, sscemi, sscvis, ssclit] = ...
                            <b>cspice_illumf</b>( ilumth(i), ...
                                            target, 'SUN', et, fixref, ...
                                            abcorr, obsrvr, sscpt );

            %
            % Convert 