title: Compute the length difference out of a longitude latitude double
body: <p>Given two gps coordinates the length difference can be calculated by using the <a href="http://www.movable-type.co.uk/scripts/latlong.html" rel="nofollow">haversine formula</a>. But what about the other way around:</p>
  
  <ul>
  <li><p>Compute the length difference in meter for a given Lat/Long double</p></li>
  <li><p>Compute the Lat/Long double for a given length in meters</p></li>
  </ul>
  
  <p>I know this is not exactly possible since it differs from the point on the earth you are, but is it possible to approximate this or something similiar? This does not have to be very precise.</p>