關於gps偏差問題及糾正算法

轉載地址：https://blog.csdn.net/weixin_33805557/article/details/88037743
用於WGS-84（地球座標系）與GCJ-02（火星座標系）的互轉：

package com.xxx.utils;
 
/** 
 * gps糾偏算法，適用於google,高德體系的地圖 
 */  
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;  
  
    /** 
     * 計算地球上任意兩點(經緯度)距離 
     *  
     * @param long1 
     *            第一點經度 
     *  
     * @param lat1 
     *            第一點緯度 
     *  
     * @param long2 
     *            第二點經度 
     *  
     * @param lat2 
     *            第二點緯度 
     *  
     * @return 返回距離 單位：米 
     */  
    public static double distance(double long1, double lat1, double long2, double lat2) {  
        double a, b, R;  
        R = 6378137; // 地球半徑  
        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;  
    }  
    
}