/* gpsutils.h -- geodesy and time conversions */ extern time_t mkgmtime(register struct tm *); extern double timestamp(void); extern double iso8601_to_unix(char *); extern char *unix_to_iso8601(double t, char *); extern double gpstime_to_unix(int, double, int); extern double earth_distance(double, double, double, double); /* return geoid separtion (MSL - WGS84) in meters, given a lat/lot in degrees */ extern double wgs84_separation(double lat, double lon);