#include <simgear/compiler.h>
-#ifdef FG_HAVE_STD_INCLUDES
+#ifdef SG_HAVE_STD_INCLUDES
# include <ctime>
#else
# include <time.h>
void fgSunPosition(time_t ssue, double *lon, double *lat);
+/* given a particular time expressed in side real time at prime
+ * meridian (GST), compute position on the earth (lat, lon) such that
+ * sun is directly overhead. (lat, lon are reported in radians */
+void fgSunPositionGST(double gst, double *lon, double *lat);
-#endif /* _SUNPOS_H */
+
+#endif /* _SUNPOS_HXX */