double ye = sun->getDoubleValue("ye");
double ze = sun->getDoubleValue("ze");
double ra = atan2(ye, xs);
double dec = atan2(ze, sqrt(xs * xs + ye * ye));
tmp = ra - (SGD_2PI/24)*gst;
double ye = sun->getDoubleValue("ye");
double ze = sun->getDoubleValue("ze");
double ra = atan2(ye, xs);
double dec = atan2(ze, sqrt(xs * xs + ye * ye));
tmp = ra - (SGD_2PI/24)*gst;