title: Android GPS locking and sensing
body: <p>I wrote an Android GPS application, that requests a location update every 20 seconds using GPS as the provider. I also added a GPS status listener to monitor the available satellites and their SNR.</p>
  
  <p>I noticed that the <code>GPSstatuslistener</code> remains updating the satellites' information all the time (i.e. not every 20 seconds)!</p>
  
  <p>My questions are:</p>
  
  <ol>
  <li>Does this mean that the GPS sensor is always on or does it sleep between every 20 second interval?</li>
  <li>The GPS location invocation consists of two stages a) locking, and b) sensing/reporting. In the android does the <code>GPSstatuslistener</code> do the locking and the <code>requestLocationUpdate</code> do the sensing?</li>
  </ol>