WGS-84：是国际标准，GPS坐标（Google Earth使用、或者GPS模块）
GCJ-02：中国坐标偏移标准，Google Map、高德、腾讯使用
BD-09：百度坐标偏移标准，Baidu Map使用
//WGS-84 to GCJ-02
GPS.gcj_encrypt();
//GCJ-02 to WGS-84 粗略
GPS.gcj_decrypt();
//GCJ-02 to WGS-84 精确(二分极限法)
// var threshold = 0.000000001; 目前设置的是精确到小数点后9位，这个值越小，越精确，但是javascript中，浮点运算本身就不太精确，九位在GPS里也偏差不大了
GSP.gcj_decrypt_exact();
//GCJ-02 to BD-09
GPS.bd_encrypt();
//BD-09 to GCJ-02
GPS.bd_decrypt();
//求距离
GPS.distance();
示例：
document.write("GPS: 39.933676862706776,116.35608315379092<br />");
var arr2 = GPS.gcj_encrypt(39.933676862706776, 116.35608315379092);
document.write("中国:" + arr2['lat']+","+arr2['lon']+'<br />');
var arr3 = GPS.gcj_decrypt_exact(arr2['lat'], arr2['lon']);
document.write('逆算:' + arr3['lat']+","+arr3['lon']+' 需要和第一行相似（目前是小数点后9位相等）');
var GPS = { PI : 3.14159265358979324, x_pi : 3.14159265358979324 * 3000.0 / 180.0, delta : function (lat, lon) { // Krasovsky 1940 // // a = 6378245.0, 1/f = 298.3 // b = a * (1 - f) // ee = (a^2 - b^2) / a^2; var a = 6378245.0; // a: 卫星椭球坐标投影到平面地图坐标系的投影因子。 var ee = 0.00669342162296594323; // ee: 椭球的偏心率。 var dLat = this.transformLat(lon - 105.0, lat - 35.0); var dLon = this.transformLon(lon - 105.0, lat - 35.0); var radLat = lat / 180.0 * this.PI; var magic = Math.sin(radLat); magic = 1 - ee * magic * magic; var sqrtMagic = Math.sqrt(magic); dLat = (dLat * 180.0) / ((a * (1 - ee)) / (magic * sqrtMagic) * this.PI); dLon = (dLon * 180.0) / (a / sqrtMagic * Math.cos(radLat) * this.PI); return {'lat': dLat, 'lon': dLon}; }, //WGS-84 to GCJ-02 gcj_encrypt : function (wgsLat, wgsLon) { if (this.outOfChina(wgsLat, wgsLon)) return {'lat': wgsLat, 'lon': wgsLon}; var d = this.delta(wgsLat, wgsLon); return {'lat' : wgsLat + d.lat,'lon' : wgsLon + d.lon}; }, //GCJ-02 to WGS-84 gcj_decrypt : function (gcjLat, gcjLon) { if (this.outOfChina(gcjLat, gcjLon)) return {'lat': gcjLat, 'lon': gcjLon}; var d = this.delta(gcjLat, gcjLon); return {'lat': gcjLat - d.lat, 'lon': gcjLon - d.lon}; }, //GCJ-02 to WGS-84 exactly gcj_decrypt_exact : function (gcjLat, gcjLon) { var initDelta = 0.01; var threshold = 0.000000001; var dLat = initDelta, dLon = initDelta; var mLat = gcjLat - dLat, mLon = gcjLon - dLon; var pLat = gcjLat + dLat, pLon = gcjLon + dLon; var wgsLat, wgsLon, i = 0; while (1) { wgsLat = (mLat + pLat) / 2; wgsLon = (mLon + pLon) / 2; var tmp = this.gcj_encrypt(wgsLat, wgsLon) dLat = tmp.lat - gcjLat; dLon = tmp.lon - gcjLon; if ((Math.abs(dLat) < threshold) && (Math.abs(dLon) < threshold)) break; if (dLat > 0) pLat = wgsLat; else mLat = wgsLat; if (dLon > 0) pLon = wgsLon; else mLon = wgsLon; if (++i > 10000) break; } //console.log(i); return {'lat': wgsLat, 'lon': wgsLon}; }, //GCJ-02 to BD-09 bd_encrypt : function (gcjLat, gcjLon) { var x = gcjLon, y = gcjLat; var z = Math.sqrt(x * x + y * y) + 0.00002 * Math.sin(y * this.x_pi); var theta = Math.atan2(y, x) + 0.000003 * Math.cos(x * this.x_pi); bdLon = z * Math.cos(theta) + 0.0065; bdLat = z * Math.sin(theta) + 0.006; return {'lat' : bdLat,'lon' : bdLon}; }, //BD-09 to GCJ-02 bd_decrypt : function (bdLat, bdLon) { var x = bdLon - 0.0065, y = bdLat - 0.006; var z = Math.sqrt(x * x + y * y) - 0.00002 * Math.sin(y * this.x_pi); var theta = Math.atan2(y, x) - 0.000003 * Math.cos(x * this.x_pi); var gcjLon = z * Math.cos(theta); var gcjLat = z * Math.sin(theta); return {'lat' : gcjLat, 'lon' : gcjLon}; }, //WGS-84 to Web mercator //mercatorLat -> y mercatorLon -> x mercator_encrypt : function(wgsLat, wgsLon) { var x = wgsLon * 20037508.34 / 180.; var y = Math.log(Math.tan((90. + wgsLat) * this.PI / 360.)) / (this.PI / 180.); y = y * 20037508.34 / 180.; return {'lat' : y, 'lon' : x}; /* if ((Math.abs(wgsLon) > 180 || Math.abs(wgsLat) > 90)) return null; var x = 6378137.0 * wgsLon * 0.017453292519943295; var a = wgsLat * 0.017453292519943295; var y = 3189068.5 * Math.log((1.0 + Math.sin(a)) / (1.0 - Math.sin(a))); return {'lat' : y, 'lon' : x}; //*/ }, // Web mercator to WGS-84 // mercatorLat -> y mercatorLon -> x mercator_decrypt : function(mercatorLat, mercatorLon) { var x = mercatorLon / 20037508.34 * 180.; var y = mercatorLat / 20037508.34 * 180.; y = 180 / this.PI * (2 * Math.atan(Math.exp(y * this.PI / 180.)) - this.PI / 2); return {'lat' : y, 'lon' : x}; /* if (Math.abs(mercatorLon) < 180 && Math.abs(mercatorLat) < 90) return null; if ((Math.abs(mercatorLon) > 20037508.3427892) || (Math.abs(mercatorLat) > 20037508.3427892)) return null; var a = mercatorLon / 6378137.0 * 57.295779513082323; var x = a - (Math.floor(((a + 180.0) / 360.0)) * 360.0); var y = (1.5707963267948966 - (2.0 * Math.atan(Math.exp((-1.0 * mercatorLat) / 6378137.0)))) * 57.295779513082323; return {'lat' : y, 'lon' : x}; //*/ }, // two point's distance distance : function (latA, lonA, latB, lonB) { var earthR = 6371000.; var x = Math.cos(latA * this.PI / 180.) * Math.cos(latB * this.PI / 180.) * Math.cos((lonA - lonB) * this.PI / 180); var y = Math.sin(latA * this.PI / 180.) * Math.sin(latB * this.PI / 180.); var s = x + y; if (s > 1) s = 1; if (s < -1) s = -1; var alpha = Math.acos(s); var distance = alpha * earthR; return distance; }, outOfChina : function (lat, lon) { if (lon < 72.004 || lon > 137.8347) return true; if (lat < 0.8293 || lat > 55.8271) return true; return false; }, transformLat : function (x, y) { var 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 * this.PI) + 20.0 * Math.sin(2.0 * x * this.PI)) * 2.0 / 3.0; ret += (20.0 * Math.sin(y * this.PI) + 40.0 * Math.sin(y / 3.0 * this.PI)) * 2.0 / 3.0; ret += (160.0 * Math.sin(y / 12.0 * this.PI) + 320 * Math.sin(y * this.PI / 30.0)) * 2.0 / 3.0; return ret; }, transformLon : function (x, y) { var 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 * this.PI) + 20.0 * Math.sin(2.0 * x * this.PI)) * 2.0 / 3.0; ret += (20.0 * Math.sin(x * this.PI) + 40.0 * Math.sin(x / 3.0 * this.PI)) * 2.0 / 3.0; ret += (150.0 * Math.sin(x / 12.0 * this.PI) + 300.0 * Math.sin(x / 30.0 * this.PI)) * 2.0 / 3.0; return ret; } };
1 class GPS { 2 private $PI = 3.14159265358979324; 3 private $x_pi = 0; 4 5 public function __construct() 6 { 7 $this->x_pi = 3.14159265358979324 * 3000.0 / 180.0; 8 } 9 //WGS-84 to GCJ-02 10 public function gcj_encrypt($wgsLat, $wgsLon) { 11 if ($this->outOfChina($wgsLat, $wgsLon)) 12 return array('lat' => $wgsLat, 'lon' => $wgsLon); 13 14 $d = $this->delta($wgsLat, $wgsLon); 15 return array('lat' => $wgsLat + $d['lat'],'lon' => $wgsLon + $d['lon']); 16 } 17 //GCJ-02 to WGS-84 18 public function gcj_decrypt($gcjLat, $gcjLon) { 19 if ($this->outOfChina($gcjLat, $gcjLon)) 20 return array('lat' => $gcjLat, 'lon' => $gcjLon); 21 22 $d = $this->delta($gcjLat, $gcjLon); 23 return array('lat' => $gcjLat - $d['lat'], 'lon' => $gcjLon - $d['lon']); 24 } 25 //GCJ-02 to WGS-84 exactly 26 public function gcj_decrypt_exact($gcjLat, $gcjLon) { 27 $initDelta = 0.01; 28 $threshold = 0.000000001; 29 $dLat = $initDelta; $dLon = $initDelta; 30 $mLat = $gcjLat - $dLat; $mLon = $gcjLon - $dLon; 31 $pLat = $gcjLat + $dLat; $pLon = $gcjLon + $dLon; 32 $wgsLat = 0; $wgsLon = 0; $i = 0; 33 while (TRUE) { 34 $wgsLat = ($mLat + $pLat) / 2; 35 $wgsLon = ($mLon + $pLon) / 2; 36 $tmp = $this->gcj_encrypt($wgsLat, $wgsLon); 37 $dLat = $tmp['lat'] - $gcjLat; 38 $dLon = $tmp['lon'] - $gcjLon; 39 if ((abs($dLat) < $threshold) && (abs($dLon) < $threshold)) 40 break; 41 42 if ($dLat > 0) $pLat = $wgsLat; else $mLat = $wgsLat; 43 if ($dLon > 0) $pLon = $wgsLon; else $mLon = $wgsLon; 44 45 if (++$i > 10000) break; 46 } 47 //console.log(i); 48 return array('lat' => $wgsLat, 'lon'=> $wgsLon); 49 } 50 //GCJ-02 to BD-09 51 public function bd_encrypt($gcjLat, $gcjLon) { 52 $x = $gcjLon; $y = $gcjLat; 53 $z = sqrt($x * $x + $y * $y) + 0.00002 * sin($y * $this->x_pi); 54 $theta = atan2($y, $x) + 0.000003 * cos($x * $this->x_pi); 55 $bdLon = $z * cos($theta) + 0.0065; 56 $bdLat = $z * sin($theta) + 0.006; 57 return array('lat' => $bdLat,'lon' => $bdLon); 58 } 59 //BD-09 to GCJ-02 60 public function bd_decrypt($bdLat, $bdLon) 61 { 62 $x = $bdLon - 0.0065; $y = $bdLat - 0.006; 63 $z = sqrt($x * $x + $y * $y) - 0.00002 * sin($y * $this->x_pi); 64 $theta = atan2($y, $x) - 0.000003 * cos($x * $this->x_pi); 65 $$gcjLon = $z * cos($theta); 66 $gcjLat = $z * sin($theta); 67 return array('lat' => $gcjLat, 'lon' => $gcjLon); 68 } 69 //WGS-84 to Web mercator 70 //$mercatorLat -> y $mercatorLon -> x 71 public function mercator_encrypt($wgsLat, $wgsLon) 72 { 73 $x = $wgsLon * 20037508.34 / 180.; 74 $y = log(tan((90. + $wgsLat) * $this->PI / 360.)) / ($this->PI / 180.); 75 $y = $y * 20037508.34 / 180.; 76 return array('lat' => $y, 'lon' => $x); 77 /* 78 if ((abs($wgsLon) > 180 || abs($wgsLat) > 90)) 79 return NULL; 80 $x = 6378137.0 * $wgsLon * 0.017453292519943295; 81 $a = $wgsLat * 0.017453292519943295; 82 $y = 3189068.5 * log((1.0 + sin($a)) / (1.0 - sin($a))); 83 return array('lat' => $y, 'lon' => $x); 84 //*/ 85 } 86 // Web mercator to WGS-84 87 // $mercatorLat -> y $mercatorLon -> x 88 public function mercator_decrypt($mercatorLat, $mercatorLon) 89 { 90 $x = $mercatorLon / 20037508.34 * 180.; 91 $y = $mercatorLat / 20037508.34 * 180.; 92 $y = 180 / $this->PI * (2 * atan(exp($y * $this->PI / 180.)) - $this->PI / 2); 93 return array('lat' => $y, 'lon' => $x); 94 /* 95 if (abs($mercatorLon) < 180 && abs($mercatorLat) < 90) 96 return NULL; 97 if ((abs($mercatorLon) > 20037508.3427892) || (abs($mercatorLat) > 20037508.3427892)) 98 return NULL; 99 $a = $mercatorLon / 6378137.0 * 57.295779513082323; 100 $x = $a - (floor((($a + 180.0) / 360.0)) * 360.0); 101 $y = (1.5707963267948966 - (2.0 * atan(exp((-1.0 * $mercatorLat) / 6378137.0)))) * 57.295779513082323; 102 return array('lat' => $y, 'lon' => $x); 103 //*/ 104 } 105 // two point's distance 106 public function distance($latA, $lonA, $latB, $lonB) 107 { 108 $earthR = 6371000.; 109 $x = cos($latA * $this->PI / 180.) * cos($latB * $this->PI / 180.) * cos(($lonA - $lonB) * $this->PI / 180); 110 $y = sin($latA * $this->PI / 180.) * sin($latB * $this->PI / 180.); 111 $s = $x + $y; 112 if ($s > 1) $s = 1; 113 if ($s < -1) $s = -1; 114 $alpha = acos($s); 115 $distance = $alpha * $earthR; 116 return $distance; 117 } 118 119 private function delta($lat, $lon) 120 { 121 // Krasovsky 1940 122 // 123 // a = 6378245.0, 1/f = 298.3 124 // b = a * (1 - f) 125 // ee = (a^2 - b^2) / a^2; 126 $a = 6378245.0;// a: 卫星椭球坐标投影到平面地图坐标系的投影因子。 127 $ee = 0.00669342162296594323;// ee: 椭球的偏心率。 128 $dLat = $this->transformLat($lon - 105.0, $lat - 35.0); 129 $dLon = $this->transformLon($lon - 105.0, $lat - 35.0); 130 $radLat = $lat / 180.0 * $this->PI; 131 $magic = sin($radLat); 132 $magic = 1 - $ee * $magic * $magic; 133 $sqrtMagic = sqrt($magic); 134 $dLat = ($dLat * 180.0) / (($a * (1 - $ee)) / ($magic * $sqrtMagic) * $this->PI); 135 $dLon = ($dLon * 180.0) / ($a / $sqrtMagic * cos($radLat) * $this->PI); 136 return array('lat' => $dLat, 'lon' => $dLon); 137 } 138 139 private function outOfChina($lat, $lon) 140 { 141 if ($lon < 72.004 || $lon > 137.8347) 142 return TRUE; 143 if ($lat < 0.8293 || $lat > 55.8271) 144 return TRUE; 145 return FALSE; 146 } 147 148 private function transformLat($x, $y) { 149 $ret = -100.0 + 2.0 * $x + 3.0 * $y + 0.2 * $y * $y + 0.1 * $x * $y + 0.2 * sqrt(abs($x)); 150 $ret += (20.0 * sin(6.0 * $x * $this->PI) + 20.0 * sin(2.0 * $x * $this->PI)) * 2.0 / 3.0; 151 $ret += (20.0 * sin($y * $this->PI) + 40.0 * sin($y / 3.0 * $this->PI)) * 2.0 / 3.0; 152 $ret += (160.0 * sin($y / 12.0 * $this->PI) + 320 * sin($y * $this->PI / 30.0)) * 2.0 / 3.0; 153 return $ret; 154 } 155 156 private function transformLon($x, $y) { 157 $ret = 300.0 + $x + 2.0 * $y + 0.1 * $x * $x + 0.1 * $x * $y + 0.1 * sqrt(abs($x)); 158 $ret += (20.0 * sin(6.0 * $x * $this->PI) + 20.0 * sin(2.0 * $x * $this->PI)) * 2.0 / 3.0; 159 $ret += (20.0 * sin($x * $this->PI) + 40.0 * sin($x / 3.0 * $this->PI)) * 2.0 / 3.0; 160 $ret += (150.0 * sin($x / 12.0 * $this->PI) + 300.0 * sin($x / 30.0 * $this->PI)) * 2.0 / 3.0; 161 return $ret; 162 } 163 }