Speed.java

// in meter
    private double calculateDistance (Location newLocation, Location oldLocation) {
    	if (newLocation.hasSpeed ()) {
    		return newLocation.getSpeed ();
		}
		
		if (oldLocation == null) {
    	    return 0;
        }
    	
        double oldLat 	= oldLocation.getLatitude ();
        double oldLng 	= oldLocation.getLongitude ();
        double newLat 	= newLocation.getLatitude ();
        double newLng 	= newLocation.getLongitude ();
        
        double dLat 	= Math.toRadians (newLat - oldLat);
        double dLon 	= Math.toRadians (newLng - oldLng);
        double a    	= Math.sin (dLat / 2) * Math.sin (dLat / 2) +
            Math.cos (Math.toRadians (oldLat)) * Math.cos (Math.toRadians (newLat)) * Math.sin (dLon / 2) * Math.sin (dLon / 2);
        
        double c    	= 2 * Math.asin (Math.sqrt (a));
        
        return Math.round (6371000 * c);
    }