/**
* Convert a latitude and longitude to easting and northing using a Transverse Mercator projection
* Formula for transformation is taken from OS document
* "A Guide to Coordinate Systems in Great Britain"
*
* @param float $scale scale factor on central meridian
* @param float $originEasting easting of true origin
* @param float $originNorthing northing of true origin
* @param float $originLat latitude of true origin
* @param float $originLong longitude of true origin
* @return array
*/
public function toTransverseMercatorEastingNorthing($scale, $originEasting, $originNorthing, $originLat, $originLong)
{
$originLat = deg2rad($originLat);
$originLong = deg2rad($originLong);
$lat = deg2rad($this->lat);
$sinLat = sin($lat);
$cosLat = cos($lat);
$tanLat = tan($lat);
$tanLatSq = pow($tanLat, 2);
$long = deg2rad($this->lng);
$n = ($this->refEll->getMaj() - $this->refEll->getMin()) / ($this->refEll->getMaj() + $this->refEll->getMin());
$nSq = pow($n, 2);
$nCu = pow($n, 3);
$v = $this->refEll->getMaj() * $scale * pow(1 - $this->refEll->getEcc() * pow($sinLat, 2), -0.5);
$p = $this->refEll->getMaj() * $scale * (1 - $this->refEll->getEcc()) * pow(1 - $this->refEll->getEcc() * pow($sinLat, 2), -1.5);
$hSq = $v / $p - 1;
$latPlusOrigin = $lat + $originLat;
$latMinusOrigin = $lat - $originLat;
$longMinusOrigin = $long - $originLong;
$M = $this->refEll->getMin() * $scale * ((1 + $n + 1.25 * ($nSq + $nCu)) * $latMinusOrigin - (3 * ($n + $nSq) + 2.625 * $nCu) * sin($latMinusOrigin) * cos($latPlusOrigin) + 1.875 * ($nSq + $nCu) * sin(2 * $latMinusOrigin) * cos(2 * $latPlusOrigin) - 35 / 24 * $nCu * sin(3 * $latMinusOrigin) * cos(3 * $latPlusOrigin));
$I = $M + $originNorthing;
$II = $v / 2 * $sinLat * $cosLat;
$III = $v / 24 * $sinLat * pow($cosLat, 3) * (5 - $tanLatSq + 9 * $hSq);
$IIIA = $v / 720 * $sinLat * pow($cosLat, 5) * (61 - 58 * $tanLatSq + pow($tanLatSq, 2));
$IV = $v * $cosLat;
$V = $v / 6 * pow($cosLat, 3) * ($v / $p - $tanLatSq);
$VI = $v / 120 * pow($cosLat, 5) * (5 - 18 * $tanLatSq + pow($tanLatSq, 2) + 14 * $hSq - 58 * $tanLatSq * $hSq);
$E = $originEasting + $IV * $longMinusOrigin + $V * pow($longMinusOrigin, 3) + $VI * pow($longMinusOrigin, 5);
$N = $I + $II * pow($longMinusOrigin, 2) + $III * pow($longMinusOrigin, 4) + $IIIA * pow($longMinusOrigin, 6);
return array('E' => $E, 'N' => $N);
}
/**
* Convert these coordinates into a latitude, longitude
* Formula for transformation is taken from OS document
* "A Guide to Coordinate Systems in Great Britain"
*
* @return LatLng
*/
public function toLatitudeLongitude()
{
$lambda = rad2deg(atan2($this->y, $this->x));
$p = sqrt(pow($this->x, 2) + pow($this->y, 2));
$phi = atan($this->z / ($p * (1 - $this->refEll->getEcc())));
do {
$phi1 = $phi;
$v = $this->refEll->getMaj() / sqrt(1 - $this->refEll->getEcc() * pow(sin($phi), 2));
$phi = atan(($this->z + $this->refEll->getEcc() * $v * sin($phi)) / $p);
} while (abs($phi - $phi1) >= 1.0E-5);
$h = $p / cos($phi) - $v;
$phi = rad2deg($phi);
return new LatLng($phi, $lambda, $h, $this->refEll);
}
public function testHelmertOSWorkedExample()
{
$tx = -446.448;
$ty = 125.157;
$tz = -542.0599999999999;
$s = 2.04894E-5;
$rx = -0.1502;
$ry = -0.247;
$rz = -0.8421;
$c = new Cartesian(3909833.018, -147097.138, 5020322.478, RefEll::wgs84());
$c->transformDatum(RefEll::airy1830(), $tx, $ty, $tz, $s, $rx, $ry, $rz);
self::assertEquals(3909460.068, round($c->getX(), 3));
self::assertEquals(-146987.302, round($c->getY(), 3));
self::assertEquals(5019888.07, round($c->getZ(), 3));
}
public function getReferenceEllipsoid()
{
return RefEll::WGS84();
}
/**
* @param int $x
* @param int $y
* @param int $z
*/
public function __construct($x, $y, $z = 0)
{
parent::__construct($x, $y, $z, RefEll::airyModified());
}
public function testNoopTransformNewYork()
{
$LatLng = new LatLng(40.7127, -74.0059, RefEll::GRS80());
$LatLngTrans = clone $LatLng;
$LatLngTrans->transformDatum(RefEll::GRS80(), RefEll::GRS80(), 0, 0, 0, 0, 0, 0, 0);
$this->assertEquals($LatLng->lat, $LatLngTrans->lat, 'Latitude transform failed');
$this->assertEquals($LatLng->lng, $LatLngTrans->lng, 'Longitude transform failed');
}
/**
* @param int $x
* @param int $y
* @param int $z
*/
public function __construct($x, $y, $z = 0)
{
parent::__construct($x, $y, $z, RefEll::grs80());
}
/**
* Convert a WGS84 latitude and longitude to an UTM reference
*
* Reference values for transformation are taken from OS document
* "A Guide to Coordinate Systems in Great Britain"
* @return UTMRef
*/
public function toUTMRef()
{
if ($this->refEll != RefEll::WGS84()) {
trigger_error('Current co-ordinates are in a non-WGS84 datum', E_USER_WARNING);
}
$longitudeZone = (int) (($this->lng + 180) / 6) + 1;
// Special zone for Norway
if ($this->lat >= 56 && $this->lat < 64 && $this->lng >= 3 && $this->lng < 12) {
$longitudeZone = 32;
}
// Special zones for Svalbard
if ($this->lat >= 72 && $this->lat < 84) {
if ($this->lng >= 0 && $this->lng < 9) {
$longitudeZone = 31;
} else {
if ($this->lng >= 9 && $this->lng < 21) {
$longitudeZone = 33;
} else {
if ($this->lng >= 21 && $this->lng < 33) {
$longitudeZone = 35;
} else {
if ($this->lng >= 33 && $this->lng < 42) {
$longitudeZone = 37;
}
}
}
}
}
$UTMZone = $this->getUTMLatitudeZoneLetter($this->lat);
$UTM = new UTMRef(0, 0, $UTMZone, $longitudeZone);
//dummy to get reference data
$scale = $UTM->getScaleFactor();
$N0 = $UTM->getOriginNorthing();
$E0 = $UTM->getOriginEasting();
$phi0 = $UTM->getOriginLatitude();
$lambda0 = $UTM->getOriginLongitude();
$coords = $this->toTransverseMercatorEastingNorthing($scale, $E0, $N0, $phi0, $lambda0);
if ($this->lat < 0) {
$coords['N'] += 10000000;
}
return new UTMRef($coords['E'], $coords['N'], $UTMZone, $longitudeZone);
}
public function getReferenceEllipsoid()
{
return RefEll::Airy1830();
}
/**
* Create a new object representing a OSGB reference.
*
* @param int $x
* @param int $y
* @param int $z
*/
public function __construct($x, $y, $z = 0)
{
parent::__construct($x, $y, $z, RefEll::airy1830());
}
