php 根據經緯度計算兩點之間的距離

/*根據經緯度計算兩點之間的距離*/

class GPSUtil
{

const  EARTH_RADIUS = 6378137;

    /**
     * @desc 根據兩點間的經緯度計算距離
     * @param float $lat 緯度值
     * @param float $lng 經度值
     */
    public static function getDistance($lat1, $lng1, $lat2, $lng2) {
        // 赤道半徑(單位m)
        $earthRadius =self::EARTH_RADIUS;

        $lat1 = ($lat1 * pi() ) / 180;

        $lng1 = ($lng1 * pi() ) / 180;

        $lat2 = ($lat2 * pi() ) / 180;

        $lng2 = ($lng2 * pi() ) / 180;

        $calcLongitude = $lng2 - $lng1;

        $calcLatitude = $lat2 - $lat1;

        $stepOne = pow(sin($calcLatitude / 2), 2) + cos($lat1) * cos($lat2) * pow(sin($calcLongitude / 2), 2);

        $stepTwo = 2 * asin(min(1, sqrt($stepOne)));

        $calculatedDistance = $earthRadius * $stepTwo;

        return abs(round($calculatedDistance/1000, 2));

    }

}