第五纬度经度点(以 php 为单位），给定初始纬度 lng、距离和方位

在php中，给定纬度和经度点，方位角（以度为单位）和距离（以英尺或公里或其他方式为单位）我如何计算出新的纬度液化点是什么？ 这是我尝试过的，但它是错误的。

function destinationPoint($lat, $lng, $brng, $dist) {
      $meters = $dist/3.2808399; // dist in meters
      $dist =  $meters/1000; // dist in km
      $rad = 6371; // earths mean radius
      $dist = $dist/$rad;  // convert dist to angular distance in radians
      $brng = deg2rad($brng);  // conver to radians 
      $lat1 = deg2rad($lat); 
      $lon1 = deg2rad($lng);
      $lat2 = asin(sin($lat1)*cos($dist) + cos($lat1)*sin($dist)*cos($brng) );
      $lon2 = $lon1 + atan2(sin($brng)*sin($dist)*cos($lat1),cos($dist)-sin($lat1)*sin($lat2));
      $lon2 = ($lon2+3*M_PI) % (2*M_PI) - M_PI;  // normalise to -180..+180º
      $lat2 = rad2deg($lat2);
      $lon2 = rad2deg($lon2);

        echo "lat2 = ".$lat2."<br/>";
        echo "lon2 = ".$lon2."<br/>";
    }