Location\Distance\Vincenty::getDistance PHP Method

    public function getDistance(Coordinate $point1, Coordinate $point2)
    {
        if ($point1->getEllipsoid() != $point2->getEllipsoid()) {
            throw new NotMatchingEllipsoidException("The ellipsoids for both coordinates must match");
        }
        $lat1 = deg2rad($point1->getLat());
        $lat2 = deg2rad($point2->getLat());
        $lng1 = deg2rad($point1->getLng());
        $lng2 = deg2rad($point2->getLng());
        $a = $point1->getEllipsoid()->getA();
        $b = $point1->getEllipsoid()->getB();
        $f = 1 / $point1->getEllipsoid()->getF();
        $L = $lng2 - $lng1;
        $U1 = atan((1 - $f) * tan($lat1));
        $U2 = atan((1 - $f) * tan($lat2));
        $iterationLimit = 100;
        $lambda = $L;
        $sinU1 = sin($U1);
        $sinU2 = sin($U2);
        $cosU1 = cos($U1);
        $cosU2 = cos($U2);
        do {
            $sinLambda = sin($lambda);
            $cosLambda = cos($lambda);
            $sinSigma = sqrt($cosU2 * $sinLambda * ($cosU2 * $sinLambda) + ($cosU1 * $sinU2 - $sinU1 * $cosU2 * $cosLambda) * ($cosU1 * $sinU2 - $sinU1 * $cosU2 * $cosLambda));
            if ($sinSigma == 0) {
                return 0.0;
            }
            $cosSigma = $sinU1 * $sinU2 + $cosU1 * $cosU2 * $cosLambda;
            $sigma = atan2($sinSigma, $cosSigma);
            $sinAlpha = $cosU1 * $cosU2 * $sinLambda / $sinSigma;
            $cosSqAlpha = 1 - $sinAlpha * $sinAlpha;
            $cos2SigmaM = 0;
            if ($cosSqAlpha != 0) {
                $cos2SigmaM = $cosSigma - 2 * $sinU1 * $sinU2 / $cosSqAlpha;
            }
            $C = $f / 16 * $cosSqAlpha * (4 + $f * (4 - 3 * $cosSqAlpha));
            $lambdaP = $lambda;
            $lambda = $L + (1 - $C) * $f * $sinAlpha * ($sigma + $C * $sinSigma * ($cos2SigmaM + $C * $cosSigma * (-1 + 2 * $cos2SigmaM * $cos2SigmaM)));
        } while (abs($lambda - $lambdaP) > 1.0E-12 && --$iterationLimit > 0);
        if ($iterationLimit == 0) {
            throw new NotConvergingException();
        }
        $uSq = $cosSqAlpha * ($a * $a - $b * $b) / ($b * $b);
        $A = 1 + $uSq / 16384 * (4096 + $uSq * (-768 + $uSq * (320 - 175 * $uSq)));
        $B = $uSq / 1024 * (256 + $uSq * (-128 + $uSq * (74 - 47 * $uSq)));
        $deltaSigma = $B * $sinSigma * ($cos2SigmaM + $B / 4 * ($cosSigma * (-1 + 2 * $cos2SigmaM * $cos2SigmaM) - $B / 6 * $cos2SigmaM * (-3 + 4 * $sinSigma * $sinSigma) * (-3 + 4 * $cos2SigmaM * $cos2SigmaM)));
        $s = $b * $A * ($sigma - $deltaSigma);
        return round($s, 3);
    }

 /**
  * Calculates the distance between 2 geometries in meters.
  *
  * @param Geometry $point_a The first point.
  * @param Geometry $point_b The second point.
  * @return float Distance in meters.
  */
 public static function distance($point_a, $point_b)
 {
     return self::apply($point_a, $point_b, function ($coor_a, $coor_b) {
         $calculator = new Vincenty();
         return $calculator->getDistance($coor_a, $coor_b);
     });
 }