Geocentric pointsΒΆ

A geocentric point is one that measures distances from the centre of the Earth. These are usually in (x,y,z) format.

A GeocentricPoint can be constructed by calling GeocentricPoint::create which has the following signature:

public static function create(
    Length $x,
    Length $y,
    Length $z,
    Geocentric $crs,
    ?DateTimeInterface $epoch = null
): GeocentricPoint

Examples:

<?php
use PHPCoord\CoordinateReferenceSystem\Geocentric;
use PHPCoord\GeocentricPoint;
use PHPCoord\UnitOfMeasure\Length\Metre;

// Ascension Island GPS tracking station in ITRF2008 (unknown date), traditional arguments
$crs = Geocentric::fromSRID(Geocentric::EPSG_ITRF2008);
$point = GeocentricPoint::create(
    new Metre(6121152),
    new Metre(-1563979),
    new Metre(-872615),
    $crs
);

// Ascension Island GPS tracking station in ITRF2008 (2020-02-01), traditional arguments
$crs = Geocentric::fromSRID(Geocentric::EPSG_ITRF2008);
$point = GeocentricPoint::create(
    new Metre(6121152),
    new Metre(-1563979),
    new Metre(-872615),
    $crs,
    new DateTime('2020-02-01')
);

// Ascension Island GPS tracking station in ITRF2008 (unknown date), named arguments
$crs = Geocentric::fromSRID(Geocentric::EPSG_ITRF2008);
$point = GeocentricPoint::create(
    x: new Metre(6121152),
    y: new Metre(-1563979),
    z: new Metre(-872615),
    crs: $crs
);

// Ascension Island GPS tracking station in ITRF2008 (2020-02-01), named arguments
$crs = Geocentric::fromSRID(Geocentric::EPSG_ITRF2008);
$point = GeocentricPoint::create(
    x: new Metre(6121152),
    y: new Metre(-1563979),
    z: new Metre(-872615),
    epoch: new DateTime('2020-02-01'),
    crs: $crs
);

$x = $point->getX(); // Length
$y = $point->getY(); // Length
$z = $point->getZ(); // Length
$epoch = $point->getCoordinateEpoch(); // DateTimeImmutable|null
$crs = $point->getCRS(); // Geocentric
$asString = (string) $point; // '(6121152, -1563979, -872615)'