Get Altitude by Longitude and Latitude in Android

Get altitude by longitude and latitude in Android

My approach is to use USGS Elevation Query Web Service:

private double getAltitude(Double longitude, Double latitude) {
    double result = Double.NaN;
    HttpClient httpClient = new DefaultHttpClient();
    HttpContext localContext = new BasicHttpContext();
    String url = "http://gisdata.usgs.gov/"
            + "xmlwebservices2/elevation_service.asmx/"
            + "getElevation?X_Value=" + String.valueOf(longitude)
            + "&Y_Value=" + String.valueOf(latitude)
            + "&Elevation_Units=METERS&Source_Layer=-1&Elevation_Only=true";
    HttpGet httpGet = new HttpGet(url);
    try {
        HttpResponse response = httpClient.execute(httpGet, localContext);
        HttpEntity entity = response.getEntity();
        if (entity != null) {
            InputStream instream = entity.getContent();
            int r = -1;
            StringBuffer respStr = new StringBuffer();
            while ((r = instream.read()) != -1)
                respStr.append((char) r);
            String tagOpen = "<double>";
            String tagClose = "</double>";
            if (respStr.indexOf(tagOpen) != -1) {
                int start = respStr.indexOf(tagOpen) + tagOpen.length();
                int end = respStr.indexOf(tagClose);
                String value = respStr.substring(start, end);
                result = Double.parseDouble(value);
            }
            instream.close();
        }
    } catch (ClientProtocolException e) {} 
    catch (IOException e) {}
    return result;
}

And example of use (right in HelloMapView class):

public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        linearLayout = (LinearLayout) findViewById(R.id.zoomview);
        mapView = (MapView) findViewById(R.id.mapview);
        mZoom = (ZoomControls) mapView.getZoomControls();
        linearLayout.addView(mZoom);
        mapView.setOnTouchListener(new OnTouchListener() {
            public boolean onTouch(View v, MotionEvent event) {
                if (event.getAction() == 1) {
                    final GeoPoint p = mapView.getProjection().fromPixels(
                            (int) event.getX(), (int) event.getY());
                    final StringBuilder msg = new StringBuilder();
                    new Thread(new Runnable() {
                        public void run() {
                            final double lon = p.getLongitudeE6() / 1E6;
                            final double lat = p.getLatitudeE6() / 1E6;
                            final double alt = getAltitude(lon, lat);
                            msg.append("Lon: ");
                            msg.append(lon);
                            msg.append(" Lat: ");
                            msg.append(lat);
                            msg.append(" Alt: ");
                            msg.append(alt);
                        }
                    }).run();
                    Toast.makeText(getBaseContext(), msg, Toast.LENGTH_SHORT)
                            .show();
                }
                return false;
            }
        });
    }

How to get Altitude from Latitude and Longitude or Google Map in Android?

You can make an HTTP call to the Google Maps Elevation API, documented at https://developers.google.com/maps/documentation/elevation/intro. I don't believe that there is native Android client library for this API. You can make a request including latitude/longitude and receive elevation information in the response.

Require altitude from latitude and longitude

I have tried the Below Way in my application for getting Altitude from Lat/Long. you can try it out if it helps you.

private double getAltitudeFromLatLong(Double lat, Double long) {
    double result = 0.0;
    HttpClient httpClient = new DefaultHttpClient();
    HttpContext Context = new BasicHttpContext();
    String URL = "http://gisdata.usgs.gov/"
            + "xmlwebservices2/elevation_service.asmx/"
            + "getElevation?X_Value=" + String.valueOf(long)
            + "&Y_Value=" + String.valueOf(lat)
            + "&Elevation_Units=METERS&Source_Layer=-1&Elevation_Only=true";
    HttpGet httpGet = new HttpGet(URL);
    try {
        HttpResponse response = httpClient.execute(httpGet, Context);
        HttpEntity entity = response.getEntity();
        if (entity != null) {
            InputStream instream = entity.getContent();
            int r = -1;
            StringBuffer respStr = new StringBuffer();
            while ((r = instream.read()) != -1)
                respStr.append((char) r);
            String tag1 = "<double>";
            String tag2 = "</double>";
            if (respStr.indexOf(tag1) != -1) {
                int start = respStr.indexOf(tag1) + tag1.length();
                int end = respStr.indexOf(tag2);
                String value = respStr.substring(start, end);
                result = Double.parseDouble(value);
            }
            instream.close();
        }
    } 
    catch (Exception e) {}
    return result;
}

How to determine my current location (longitude,latitude and altitude)?

First Enable Ur GPS.

    private static final long MINIMUM_DISTANCE_CHANGE_FOR_UPDATES = 1; // in Meters
    private static final long MINIMUM_TIME_BETWEEN_UPDATES = 1000; // in Milliseconds

    public static double lontitube,latitude;

    protected LocationManager locationManager;
    protected Location currentLocation;
 public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);

        locationManager.requestLocationUpdates(
                LocationManager.GPS_PROVIDER, 
                MINIMUM_TIME_BETWEEN_UPDATES, 
                MINIMUM_DISTANCE_CHANGE_FOR_UPDATES,
                new MyLocationListener()
        );
}

 protected void performReverseGeocodingInBackground() {
        showCurrentLocation();

    }

    protected void showCurrentLocation() {

        currentLocation = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);

        if (currentLocation != null) {
            String message = String.format(
                    "Current Location \n Longitude: %1$s \n Latitude: %2$s",
                    currentLocation.getLongitude(), currentLocation.getLatitude()

            );
            lontitube=currentLocation.getLongitude();
            latitude=currentLocation.getLatitude();

            System.out.println("----lati----longi----"+latitude+"\n"+lontitube);

               Toast.makeText(Demo.this, message,
               Toast.LENGTH_LONG).show();
        }

    }   

    private class MyLocationListener implements LocationListener {

        public void onLocationChanged(Location location) {

       String message = String.format(
                    "New Location \n Longitude: %1$s \n Latitude: %2$s",
                    location.getLongitude(), location.getLatitude()
            );
            Toast.makeText(Demo.this, message, Toast.LENGTH_LONG).show();
        }

        public void onStatusChanged(String s, int i, Bundle b) {
            Toast.makeText(Demo.this, "Provider status changed",
                    Toast.LENGTH_LONG).show();
        }

        public void onProviderDisabled(String s) {
            Toast.makeText(Demo.this,
                    "Provider disabled by the user. GPS turned off",
                    Toast.LENGTH_LONG).show();
        }

        public void onProviderEnabled(String s) {
            Toast.makeText(Demo.this,
                    "Provider enabled by the user. GPS turned on",
                    Toast.LENGTH_LONG).show();
        }

    }

In AndroidManifest add

ACCESS_FINE_LOCATION

permission for GPS use.

<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />

Android how to get altitude in LocationManager. i am alwaya getting zero

What method did u used to get the location?
Maybe u could try http://developer.android.com/reference/android/location/LocationManager.html#getLastKnownLocation(java.lang.String) instead, that worked for me.

If not, maybe try another approach, there are several ones:
http://developer.android.com/guide/topics/location/index.html

BTW: could u give us some code? On what device are you testing?

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