利用GPS坐标进行测距

Question

如何利用GPS坐标计算两地之间的距离？

Answer 1

你必须使用哈维正弦公式:哈维正弦公式：

R=地球半径(平均半径=6,371千米)

lat lat=Δ2−lat1

Δlong =long 2−long1

A=sin²(长整度/2)+ cos(lat1).cos(lat2).sin²(Δlong/2)

C= 2.atan2(√a，√(1−a))

D= R.c

其中d是距离(您的解决方案)，所有角度都必须是弧度。

查找haversine库，在C：

#include <math.h>
#include "haversine.h"

#define d2r (M_PI / 180.0)

//calculate haversine distance for linear distance
double haversine_km(double lat1, double long1, double lat2, double long2)
{
    double dlong = (long2 - long1) * d2r;
    double dlat = (lat2 - lat1) * d2r;
    double a = pow(sin(dlat/2.0), 2) + cos(lat1*d2r) * cos(lat2*d2r) * pow(sin(dlong/2.0), 2);
    double c = 2 * atan2(sqrt(a), sqrt(1-a));
    double d = 6367 * c;

    return d;
}

double haversine_mi(double lat1, double long1, double lat2, double long2)
{
    double dlong = (long2 - long1) * d2r;
    double dlat = (lat2 - lat1) * d2r;
    double a = pow(sin(dlat/2.0), 2) + cos(lat1*d2r) * cos(lat2*d2r) * pow(sin(dlong/2.0), 2);
    double c = 2 * atan2(sqrt(a), sqrt(1-a));
    double d = 3956 * c; 

    return d;
}

Answer 2

http://en.wikipedia.org/wiki/

(由于地球的球形性，毕达哥拉斯定理是不够的)