geo.h

计算地理距离和方位角的程序

//	geo.h
//

#ifndef GEO_CALCULATIONS_H_
#define GEO_CALCULATIONS_H_

  //
  // some geo constants
  //

namespace GEO {
	const double PI = 3.14159265359;
	const double TWOPI = 6.28318530718;
	const double DE2RA = 0.01745329252;
	const double RA2DE = 57.2957795129;
	const double ERAD = 6378.135;
	const double ERADM = 6378135.0;
	const double AVG_ERAD = 6371.0;
	const double FLATTENING = 1.0/298.26;// Earth flattening (WGS '72)
	const double EPS = 0.000000000005;
	const double KM2MI = 0.621371;
}

double GCDistance(double lat1, double lon1, double lat2, double lon2);

double ApproxDistance(double lat1, double lon1, double lat2, double lon2);

double EllipsoidDistance(double lat1, double lon1, double lat2, double lon2);

double GCAzimuth(double lat1, double lon1, double lat2, double lon2);

double EllipsoidAzimuth(double lat1, double lon1, double lat2, double lon2);

double ApproxAzimuth(double lat1, double lon1, double lat2, double lon2);

#endif