package com.xxx.utils;

/**

* gps纠偏算法，适用于google,高德体系的地图

*/

public abstract class GpsUtil {

private final static double a = 6378245.0;

private final static double pi = 3.14159265358979324;

private final static double ee = 0.00669342162296594323;

/**

* 计算地球上任意两点(经纬度)距离

*

* @param long1

* 第一点经度

*

* @param lat1

* 第一点纬度

*

* @param long2

* 第二点经度

*

* @param lat2

* 第二点纬度

*

* @return 返回距离 单位：米

*/

public static double distance(double long1, double lat1, double long2, double lat2) {

double a, b, R;

R = 6378137; // 地球半径

lat1 = lat1 * Math.PI / 180.0;

lat2 = lat2 * Math.PI / 180.0;

a = lat1 - lat2;

b = (long1 - long2) * Math.PI / 180.0;

double d;

double sa2, sb2;

sa2 = Math.sin(a / 2.0);

sb2 = Math.sin(b / 2.0);

d = 2 * R * Math.asin(Math.sqrt(sa2 * sa2 + Math.cos(lat1) * Math.cos(lat2) * sb2 * sb2));

return d;

}

/** WGS-84 to GCJ-02 */

public static double[] toGCJ02Point(double latitude, double longitude) {

double[] dev = calDev(latitude, longitude);

double retLat = latitude + dev[0];

double retLon = longitude + dev[1];

return new double[] { retLat, retLon };

}

/** GCJ-02 to WGS-84 */

public static double[] toWGS84Point(double latitude, double longitude) {

double[] dev = calDev(latitude, longitude);

double retLat = latitude - dev[0];

double retLon = longitude - dev[1];

dev = calDev(retLat, retLon);

retLat = latitude - dev[0];

retLon = longitude - dev[1];

return new double[] { retLat, retLon };

}

private static double[] calDev(double wgLat, double wgLon) {

if (isOutOfChina(wgLat, wgLon)) {

return new double[] { 0, 0 };

}

double dLat = calLat(wgLon - 105.0, wgLat - 35.0);

double dLon = calLon(wgLon - 105.0, wgLat - 35.0);

double radLat = wgLat / 180.0 * pi;

double magic = Math.sin(radLat);

magic = 1 - ee * magic * magic;

double sqrtMagic = Math.sqrt(magic);

dLat = (dLat * 180.0) / ((a * (1 - ee)) / (magic * sqrtMagic) * pi);

dLon = (dLon * 180.0) / (a / sqrtMagic * Math.cos(radLat) * pi);

return new double[] { dLat, dLon };

}

private static boolean isOutOfChina(double lat, double lon) {

if (lon < 72.004 || lon > 137.8347)

return true;

if (lat < 0.8293 || lat > 55.8271)

return true;

return false;

}

private static double calLat(double x, double y) {

double ret = -100.0 + 2.0 * x + 3.0 * y + 0.2 * y * y + 0.1 * x * y + 0.2 * Math.sqrt(Math.abs(x));

ret += (20.0 * Math.sin(6.0 * x * pi) + 20.0 * Math.sin(2.0 * x * pi)) * 2.0 / 3.0;

ret += (20.0 * Math.sin(y * pi) + 40.0 * Math.sin(y / 3.0 * pi)) * 2.0 / 3.0;

ret += (160.0 * Math.sin(y / 12.0 * pi) + 320 * Math.sin(y * pi / 30.0)) * 2.0 / 3.0;

return ret;

}

private static double calLon(double x, double y) {

double ret = 300.0 + x + 2.0 * y + 0.1 * x * x + 0.1 * x * y + 0.1 * Math.sqrt(Math.abs(x));

ret += (20.0 * Math.sin(6.0 * x * pi) + 20.0 * Math.sin(2.0 * x * pi)) * 2.0 / 3.0;

ret += (20.0 * Math.sin(x * pi) + 40.0 * Math.sin(x / 3.0 * pi)) * 2.0 / 3.0;

ret += (150.0 * Math.sin(x / 12.0 * pi) + 300.0 * Math.sin(x / 30.0 * pi)) * 2.0 / 3.0;

return ret;

}

}