缘由：常见各种坐标系由来和对应关系
WGS84、Web墨卡托、火星坐标、百度坐标互转
http://blog.csdn.net/wildboy2001/article/details/12031351
自己取的点为什么在地图上显示不准？
http://lbs.amap.com/home/faq/%E5%9D%90%E6%A0%87%E4%BD%93%E7%B3%BB/#Q03
常见坐标系对应关系
1.GPS/原始坐标系 WGS-84
2.百度 /加密坐标系 BD-09
3.谷歌/腾讯 GCJ-02
转换类
声明:类为复制
<?php
/**
* 1.GPS/原始坐标系 WGS-84
* 2.百度 /加密坐标系 BD-09
* 3.谷歌/腾讯 GCJ-02
*/
class GPS {
private $PI = 3.14159265358979324;
private $x_pi = 0;
public function __construct() {
$this->x_pi = 3.14159265358979324 * 3000.0 / 180.0;
}
// WGS-84 to GCJ-02
public function gcj_encrypt($wgsLat, $wgsLon) {
if ($this->outOfChina ( $wgsLat, $wgsLon ))
return array (
'lat' => $wgsLat,
'lon' => $wgsLon
);
$d = $this->delta ( $wgsLat, $wgsLon );
return array (
'lat' => $wgsLat + $d ['lat'],
'lon' => $wgsLon + $d ['lon']
);
}
// GCJ-02 to WGS-84
public function gcj_decrypt($gcjLat, $gcjLon) {
if ($this->outOfChina ( $gcjLat, $gcjLon ))
return array (
'lat' => $gcjLat,
'lon' => $gcjLon
);
$d = $this->delta ( $gcjLat, $gcjLon );
return array (
'lat' => $gcjLat - $d ['lat'],
'lon' => $gcjLon - $d ['lon']
);
}
// GCJ-02 to WGS-84 exactly
public function gcj_decrypt_exact($gcjLat, $gcjLon) {
$initDelta = 0.01;
$threshold = 0.000000001;
$dLat = $initDelta;
$dLon = $initDelta;
$mLat = $gcjLat - $dLat;
$mLon = $gcjLon - $dLon;
$pLat = $gcjLat + $dLat;
$pLon = $gcjLon + $dLon;
$wgsLat = 0;
$wgsLon = 0;
$i = 0;
while ( TRUE ) {
$wgsLat = ($mLat + $pLat) / 2;
$wgsLon = ($mLon + $pLon) / 2;
$tmp = $this->gcj_encrypt ( $wgsLat, $wgsLon );
$dLat = $tmp ['lat'] - $gcjLat;
$dLon = $tmp ['lon'] - $gcjLon;
if ((abs ( $dLat ) < $threshold) && (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 array (
'lat' => $wgsLat,
'lon' => $wgsLon
);
}
// GCJ-02 to BD-09
public function bd_encrypt($gcjLat, $gcjLon) {
$x = $gcjLon;
$y = $gcjLat;
$z = sqrt ( $x * $x + $y * $y ) + 0.00002 * sin ( $y * $this->x_pi );
$theta = atan2 ( $y, $x ) + 0.000003 * cos ( $x * $this->x_pi );
$bdLon = $z * cos ( $theta ) + 0.0065;
$bdLat = $z * sin ( $theta ) + 0.006;
return array (
'lat' => $bdLat,
'lon' => $bdLon
);
}
// BD-09 to GCJ-02
public function bd_decrypt($bdLat, $bdLon) {
$x = $bdLon - 0.0065;
$y = $bdLat - 0.006;
$z = sqrt ( $x * $x + $y * $y ) - 0.00002 * sin ( $y * M_PI );
$theta = atan2 ( $y, $x ) - 0.000003 * cos ( $x * M_PI );
$gg_lon = $z * cos ( $theta );
$gg_lat = $z * sin ( $theta );
// 方式2
return array (
'lat' => $gg_lat,
'lon' => $gg_lon
);
//
$x = $bdLon - 0.0065;
$y = $bdLat - 0.006;
$z = sqrt ( $x * $x + $y * $y ) - 0.00002 * sin ( $y * $this->x_pi );
$theta = atan2 ( $y, $x ) - 0.000003 * cos ( $x * $this->x_pi );
$$gcjLon = $z * cos ( $theta );
$gcjLat = $z * sin ( $theta );
return array (
'lat' => $gcjLat,
'lon' => $gcjLon
);
}
public function bd_decrypt_lat($bdLat, $bdLon) {
$result = $this->bd_decrypt ( $bdLat, $bdLon );
return $result ['lat'];
}
public function bd_decrypt_lon($bdLat, $bdLon) {
$result = $this->bd_decrypt ( $bdLat, $bdLon );
return $result ['lon'];
}
// WGS-84 to Web mercator
// $mercatorLat -> y $mercatorLon -> x
public function mercator_encrypt($wgsLat, $wgsLon) {
$x = $wgsLon * 20037508.34 / 180.;
$y = log ( tan ( (90. + $wgsLat) * $this->PI / 360. ) ) / ($this->PI / 180.);
$y = $y * 20037508.34 / 180.;
return array (
'lat' => $y,
'lon' => $x
);
/*
* if ((abs($wgsLon) > 180 || abs($wgsLat) > 90)) return NULL; $x =
* 6378137.0 * $wgsLon * 0.017453292519943295; $a = $wgsLat *
* 0.017453292519943295; $y = 3189068.5 * log((1.0 + sin($a)) / (1.0 -
* sin($a))); return array('lat' => $y, 'lon' => $x); //
*/
}
// Web mercator to WGS-84
// $mercatorLat -> y $mercatorLon -> x
public function mercator_decrypt($mercatorLat, $mercatorLon) {
$x = $mercatorLon / 20037508.34 * 180.;
$y = $mercatorLat / 20037508.34 * 180.;
$y = 180 / $this->PI * (2 * atan ( exp ( $y * $this->PI / 180. ) ) - $this->PI / 2);
return array (
'lat' => $y,
'lon' => $x
);
/*
* if (abs($mercatorLon) < 180 && abs($mercatorLat) < 90) return NULL;
* if ((abs($mercatorLon) > 20037508.3427892) || (abs($mercatorLat) >
* 20037508.3427892)) return NULL; $a = $mercatorLon / 6378137.0 *
* 57.295779513082323; $x = $a - (floor((($a + 180.0) / 360.0)) *
* 360.0); $y = (1.5707963267948966 - (2.0 * atan(exp((-1.0 *
* $mercatorLat) / 6378137.0)))) * 57.295779513082323; return
* array('lat' => $y, 'lon' => $x); //
*/
}
// two point's distance
public function distance($latA, $lonA, $latB, $lonB) {
$earthR = 6371000.;
$x = cos ( $latA * $this->PI / 180. ) * cos ( $latB * $this->PI / 180. ) * cos ( ($lonA - $lonB) * $this->PI / 180 );
$y = sin ( $latA * $this->PI / 180. ) * sin ( $latB * $this->PI / 180. );
$s = $x + $y;
if ($s > 1)
$s = 1;
if ($s < - 1)
$s = - 1;
$alpha = acos ( $s );
$distance = $alpha * $earthR;
return $distance;
}
private function delta($lat, $lon) {
// Krasovsky 1940
//
// a = 6378245.0, 1/f = 298.3
// b = a * (1 - f)
// ee = (a^2 - b^2) / a^2;
$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。
$ee = 0.00669342162296594323; // ee: 椭球的偏心率。
$dLat = $this->transformLat ( $lon - 105.0, $lat - 35.0 );
$dLon = $this->transformLon ( $lon - 105.0, $lat - 35.0 );
$radLat = $lat / 180.0 * $this->PI;
$magic = sin ( $radLat );
$magic = 1 - $ee * $magic * $magic;
$sqrtMagic = sqrt ( $magic );
$dLat = ($dLat * 180.0) / (($a * (1 - $ee)) / ($magic * $sqrtMagic) * $this->PI);
$dLon = ($dLon * 180.0) / ($a / $sqrtMagic * cos ( $radLat ) * $this->PI);
return array (
'lat' => $dLat,
'lon' => $dLon
);
}
private function outOfChina($lat, $lon) {
if ($lon < 72.004 || $lon > 137.8347)
return TRUE;
if ($lat < 0.8293 || $lat > 55.8271)
return TRUE;
return FALSE;
}
private function transformLat($x, $y) {
$ret = - 100.0 + 2.0 * $x + 3.0 * $y + 0.2 * $y * $y + 0.1 * $x * $y + 0.2 * sqrt ( abs ( $x ) );
$ret += (20.0 * sin ( 6.0 * $x * $this->PI ) + 20.0 * sin ( 2.0 * $x * $this->PI )) * 2.0 / 3.0;
$ret += (20.0 * sin ( $y * $this->PI ) + 40.0 * sin ( $y / 3.0 * $this->PI )) * 2.0 / 3.0;
$ret += (160.0 * sin ( $y / 12.0 * $this->PI ) + 320 * sin ( $y * $this->PI / 30.0 )) * 2.0 / 3.0;
return $ret;
}
private function transformLon($x, $y) {
$ret = 300.0 + $x + 2.0 * $y + 0.1 * $x * $x + 0.1 * $x * $y + 0.1 * sqrt ( abs ( $x ) );
$ret += (20.0 * sin ( 6.0 * $x * $this->PI ) + 20.0 * sin ( 2.0 * $x * $this->PI )) * 2.0 / 3.0;
$ret += (20.0 * sin ( $x * $this->PI ) + 40.0 * sin ( $x / 3.0 * $this->PI )) * 2.0 / 3.0;
$ret += (150.0 * sin ( $x / 12.0 * $this->PI ) + 300.0 * sin ( $x / 30.0 * $this->PI )) * 2.0 / 3.0;
return $ret;
}
}