title: transform longitude latitude into meters
body: <p>I need a function that maps gps positions to x/y values like this:</p>
  
  <pre><code>getXYpos(GeoPoint relativeNullPoint, GeoPoint p){
     deltaLatitude=p.latitude-relativeNullPoint.latitude;
     deltaLongitude=p.longitude-relativeNullPoint.longitude;
     ...
     resultX=latitude (or west to east) distance in meters from p to relativeNullPoint
     resultY=longitude (or south to north) distance in meters from p to relativeNullPoint
  }
  </code></pre>
  
  <p>i have seen some implementations of "distance of two geoPoints" but they all just calculate the air-line distance.
  i think the deltaLongitude can be transformed into meters directly but the deltaLatitude depends in the Longitude. does anyone know how this problem can be solved?</p>