title: How does getAltitude() of Android GPS Location Works
body: <p>HI</p>
  
  <p>I tried to implement a simple GPS tracker. Therefore is used </p>
  
  <pre><code>lm = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
  lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 1000, 0, this);  
  </code></pre>
  
  <p>Then i used the</p>
  
  <pre><code>public void onLocationChanged(Location location) {
  </code></pre>
  
  <p>method to read the altitude of my current location.</p>
  
  <p>But i dont really know what Location.getAltitude() returns. The document says it returns the altitude. But is this in meters? or feets? if i put the phone on the desk next to me, this value changes between 500 and -500??</p>
  
  <p>How does this really work???</p>