这篇文章主要介绍了经纬度bl和直角坐标xy的正算反算 php代码，有着一定的参考价值，现在分享给大家，有需要的朋友可以参考一下
这里是用的北京54坐标6度分带。需要用其他坐标可以修改参数$_a, $_f 。
经纬度转xy：
<?php
function bltoxy($latitude, $longitude)
{
$_a = 6378245.0;
$_f = 1.0 / 298.3;
$zonewide = 6;
$pi = 3.14159265353846;
$ipi = 0.0174532925199433; //3.1415926535898/180.0;
//zonewide = 6; //6度带宽
$projno = floor($longitude / $zonewide);
$longitude0 = $projno * $zonewide + $zonewide / 2;
$longitude0 = $longitude0 * $ipi;
$latitude0 = 0;
$longitude1 = $longitude * $ipi; //经度转换为弧度
$latitude1 = $latitude * $ipi; //纬度转换为弧度
$e2 = 2 * $_f - $_f * $_f;
$ee = $e2 * (1.0 - $e2);
$nn = $_a / sqrt(1.0 - $e2 * sin($latitude1) * sin($latitude1));
$t = tan($latitude1) * tan($latitude1);
$c = $ee * cos($latitude1) * cos($latitude1);
$a = ($longitude1 - $longitude0) * cos($latitude1);
$m = $_a * ((1 - $e2 / 4 - 3 * $e2 * $e2 / 64 - 5 * $e2 * $e2 * $e2 / 256) * $latitude1 - (3 * $e2 / 8 + 3 * $e2 * $e2 / 32 + 45 * $e2 * $e2 * $e2 / 1024) * sin(2 * $latitude1) + (15 * $e2 * $e2 / 256 + 45 * $e2 * $e2 * $e2 / 1024) * sin(4 * $latitude1) - (35 * $e2 * $e2 * $e2 / 3072) * sin(6 * $latitude1));
$xval = $nn * ($a + (1 - $t + $c) * $a * $a * $a / 6 + (5 - 18 * $t + $t * $t + 72 * $c - 58 * $ee) * $a * $a * $a * $a * $a / 120);
$yval = $m + $nn * tan($latitude1) * ($a * $a / 2 + (5 - $t + 9 * $c + 4 * $c * $c) * $a * $a * $a * $a / 24 + (61 - 58 * $t + $t * $t + 600 * $c - 330 * $ee) * $a * $a * $a * $a * $a * $a / 720);
$x0 = 1000000 * ($projno + 1) + 500000;
$y0 = 0;
$x = round(($xval + $x0) * 100) / 100.0;
$y = round(($yval + $y0) * 100) / 100.0;
return array($x, $y);
}
$lng = $_get["lng"];
$lat = $_get["lat"];
$xy = bltoxy($lat, $lng);
echo json_encode($xy);
?>
xy转经纬度：
<?php
function xytobl($x, $y)
{
$_a = 6378245.0;
$_f = 1.0 / 298.3;
$zonewide = 6;
$pi = 3.14159265353846;
$ipi = 0.0174532925199433; //3.1415926535898/180.0;
$projno = floor($x / 1000000.0); //查找带号
$longitude0 = ($projno - 1) * $zonewide + $zonewide / 2;
$longitude0 = $longitude0 * $ipi; //中央经线
$x0 = $projno * 1000000 + 500000;
$y0 = 0;
$xval = $x - $x0;
$yval = $y - $y0; //带内大地坐标
$e2 = 2 * $_f - $_f * $_f;
$e1 = (1.0 - sqrt(1 - $e2)) / (1.0 + sqrt(1 - $e2));
$ee = $e2 / (1 - $e2);
$m = $yval;
$u = $m / ($_a * (1 - $e2 / 4 - 3 * $e2 * $e2 / 64 - 5 * $e2 * $e2 * $e2 / 256));
$fai = $u + (3 * $e1 / 2 - 27 * $e1 * $e1 * $e1 / 32) * sin(2 * $u) + (21 * $e1 * $e1 / 16 - 55 * $e1 * $e1 * $e1 * $e1 / 32) * sin(4 * $u) + (151 * $e1 * $e1 * $e1 / 96) * sin(6 * $u) + (1097 * $e1 * $e1 * $e1 * $e1 / 512) * sin(8 * $u);
$c = $ee * cos($fai) * cos($fai);
$t = tan($fai) * tan($fai);
$nn = $_a / sqrt(1.0 - $e2 * sin($fai) * sin($fai));
$r = $_a * (1 - $e2) / sqrt((1 - $e2 * sin($fai) * sin($fai)) * (1 - $e2 * sin($fai) * sin($fai)) * (1 - $e2 * sin($fai) * sin($fai)));
$d = $xval / $nn;
//计算经度(longitude) 纬度(latitude)
$longitude1 = $longitude0 + ($d - (1 + 2 * $t + $c) * $d * $d * $d / 6 + (5 - 2 * $c + 28 * $t - 3 * $c * $c + 8 * $ee + 24 * $t * $t) * $d * $d * $d * $d * $d / 120) / cos($fai);
$latitude1 = $fai - ($nn * tan($fai) / $r) * ($d * $d / 2 - (5 + 3 * $t + 10 * $c - 4 * $c * $c - 9 * $ee) * $d * $d * $d * $d / 24 + (61 + 90 * $t + 298 * $c + 45 * $t * $t - 256 * $ee - 3 * $c * $c) * $d * $d * $d * $d * $d * $d / 720);
//转换为度 dd
$longitude = round(($longitude1 / $ipi) * 1000000) / 1000000.0;
$latitude = round(($latitude1 / $ipi) * 1000000) / 1000000.0;
return array($longitude, $latitude);
}
$x = $_get["x"];
$y = $_get["y"];
$latlng = xytobl($x, $y);
echo json_encode($latlng);
?>
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以上就是经纬度bl和直角坐标xy的正算反算 php代码的详细内容。