Sean Sean - 15 days ago 7
Android Question

I keep getting an inaccurate location in Android

my app records the gps location on a button click; however when I do it says I'm about three blocks away and is extremely inaccurate. Can you take a look at my code to see how I can improve it? Thanks

@Override
protected Void doInBackground(Void... arg0) {
SharedPreferences prefs = getSharedPreferences("Settings", 0);
final String id = prefs.getString("ID", "");
DefaultHttpClient httpclient = new DefaultHttpClient();
HttpPost httpost = new HttpPost(
"http://iphone-radar.com/gps/gps_locations");

JSONObject holder = new JSONObject();

try {
holder.put("id", id);
LocationManager locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
Criteria criteria = new Criteria();
String bestProvider = locationManager.getBestProvider(criteria,
false);
LocationListener loc_listener=new LocationListener() {

@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
// TODO Auto-generated method stub

}

@Override
public void onProviderEnabled(String provider) {
// TODO Auto-generated method stub

}

@Override
public void onProviderDisabled(String provider) {
// TODO Auto-generated method stub

}

@Override
public void onLocationChanged(Location location) {
// TODO Auto-generated method stub

}
};
try{
Looper.prepare();
locationManager.requestLocationUpdates(bestProvider, 0, 0, loc_listener);
}catch(Exception e){
e.printStackTrace();
}
Location location=locationManager.

getLastKnownLocation(bestProvider);
Calendar c = Calendar.getInstance();
SimpleDateFormat sdf = new SimpleDateFormat("hh:mmaa dd'/'MM'/'yyyy");

holder.put("time", sdf.format(c.getTime()));
holder.put("time_since_epoch", System.currentTimeMillis());
try {
holder.put("lat", location.getLatitude());
holder.put("lon", location.getLongitude());
} catch (NullPointerException e) {
try {
holder.put("lat", -1.0);
holder.put("lon", -1.0);
} catch (JSONException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
}

StringEntity se = new StringEntity(holder.toString());
httpost.setEntity(se);
httpost.setHeader("Accept", "application/json");
httpost.setHeader("Content-type", "application/json");

ResponseHandler responseHandler = new BasicResponseHandler();
String response = httpclient.execute(httpost, responseHandler);
org.json.JSONObject obj;

obj = new org.json.JSONObject(response);

} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (UnsupportedEncodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

Answer

Yes there absolutely is, try adding some accuracy to your Criteria...

Criteria criteria = new Criteria();
criteria.setAccuracy(Criteria.ACCURACY_FINE);

The default constructor for Criteria states (emphasis mine)

Constructs a new Criteria object. The new object will have no requirements on accuracy, power, or response time; will not require altitude, speed, or bearing; and will not allow monetary cost.