Positive calculation of the latitude BL and cartesian coordinates xy PHP code

This article mainly introduces the latitude and longitude bl and Cartesian coordinates XY of the positive calculation of PHP code, has a certain reference value, now share to everyone, the need for friends can refer to

Here is the Beijing 54 coordinate 6 degree belt. You need to use other coordinates to modify the parameter $_a, $_f.

By Latitude to XY:

<?phpfunction 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-degree bandwidth $ProjNo = floor ($longitude/$zoneWide);        $longitude 0 = $ProjNo * $zoneWide + $zoneWide/2;        $longitude 0 = $longitude 0 * $iPI;        $latitude 0 = 0; $longitude 1 = $longitude * $iPI; The longitude is converted to radians $latitude 1 = $latitude * $iPI;        Latitude converted to radians $e 2 = 2 * $_f-$_f * $_F;        $ee = $e 2 * (1.0-$e 2);        $NN = $_a/sqrt (1.0-$e 2 * sin ($latitude 1) * sin ($latitude 1));        $T = tan ($latitude 1) * TAN ($latitude 1);        $C = $ee * cos ($latitude 1) * cos ($latitude 1);        $A = ($longitude 1-$longitude 0) * cos ($latitude 1); $M = $_a * ((1-$e 2/4-3 * $e 2 * $e 2/64-5 * $e 2 * $e 2 * $e 2/256) * $latitude 1-(3 * $e 2/8 + 3 * $e 2 * $e 2/3 2 + * $e 2 * $e 2 * $e 2/1024) * SIN (2 * $latitude 1) + (15 * $e 2 * $e 2/256 + * $e 2 * $e 2 * $e 2/1024) * SIN (4 * $latitude 1)-(* $e 2 * $e 2 * $e 2/3072) * SIN (6 * $latitud        E1)); $xval = $NN * ($A + (1-$T + $C) * $A * $A * $A/6 + (5-18 * $T + $T * $T + * * $C -58 * $ee) * $A * $A * $A * $A *        $A/120); $yval = $M + $NN * TAN ($latitude 1) * ($A * $A/2 + (+ $T + 9 * $C + 4 * $C * $C) * $A * $A * $A * $A/24 + (61-58 *        $T + $T * $T + $ * $C -330 * $ee) * $A * $A * $A * $A * $A * $A/720);        $X 0 = 1000000 * ($ProjNo + 1) + 500000;        $Y 0 = 0;            $X = Round (($xval + $X 0) * 100)/100.0; $Y = Round (($yval + $Y 0) * +)/100.0;return Array ($X, $Y);} $LNG = $_get["LNG"); $lat = $_get["lat"]; $XY = Bltoxy ($lat, $LNG); Echo Json_encode ($XY);? >

XY warp Latitude:

<?phpfunction 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);        Look for the band number $longitude 0 = ($ProjNo-1) * $zoneWide + $zoneWide/2; $longitude 0 = $longitude 0 * $iPI;        Central Meridian $X 0 = $ProjNo * 1000000 + 500000;        $Y 0 = 0;        $xval = $X-$X 0; $yval = $Y-$Y 0;        In-band geodetic coordinates $e 2 = 2 * $_f-$_f * $_F;        $e 1 = (1.0-sqrt (1-$e 2))/(1.0 + sqrt (1-$e 2));        $ee = $e 2/(1-$e 2);        $M = $yval;        $u = $M/($_A * (1-$e 2/4-3 * $e 2 * $e 2/64-5 * $e 2 * $e 2 * $e 2/256)); $fai = $u + (3 * $e $e 1 * $e 1 * $e 1/32) * SIN (2 * $u) + (* $e 1 * $e 1/16-55 * $e 1 * $e 1 * $e 1 * $e 1/        * SIN (4 * $u) + (151 * $e 1 * $e 1 * $e 1/96) * SIN (6 * $u) + (1097 * $e 1 * $e 1 * $e 1 * $e 1/512) * SIN (8 * $u);        $C = $ee * cos ($FAI) * cos ($FAI); $T= Tan ($fai) * TAN ($FAI);        $NN = $_a/sqrt (1.0-$e 2 * sin ($fai) * sin ($fai));  $R = $_a * (1-$e 2)/sqrt ((1-$e 2 * sin ($fai) * sin ($FAI)) * (1-$e 2 * sin ($fai) * sin ($FAI)) * (1-$e 2 * sin ($FAI) *        Sin ($fai)));        $D = $xval/$NN;  Calculate longitude (longitude) latitude (Latitude) $longitude 1 = $longitude 0 + ($D-(1 + 2 * $T + $C) * $D * $D * $D/6 + (5-2 * $C        + * $T-3 * $C * $C + 8 * $ee + * $T * $T) * $D * $D * $D * $D * $D/120)/cos ($FAI); $latitude 1 = $fai-($NN * TAN ($FAI)/$R) * ($D * $D/2-(5 + 3 * $T + ten * $C-4 * $C * $C-9 * $ee) * $D * $D * $D        * $D/24 + * $T + 298 * $C + * $T * $T -256 * $ee-3 * $C * $C) * $D * $D * $D * $D * $D * $D/720);        Convert to degrees DD $longitude = Round (($longitude 1/$iPI) * 1000000)/1000000.0; $latitude = Round (($latitude 1/$iPI) * 1000000)/1000000.0;return Array ($longitude, $latitude);} $X = $_get["X"]; $Y = $_get["Y"]; $latlng = Xytobl ($X, $Y); Echo Json_encode ($LATLNG);?>