Setting locations latitude & longitude in facing direction

Question

How do you clone your own Location, and then add some extra metres towards a desired direction?

Right now my android app can get the azimut, and my GPS location, and I hardcoded the desired distanct for an example, 10 metres.

Then my app should create a new Location, exactly 10 metres ahead where im facing.

So if my position is: longitude 17.537200603552526, latitude 25.70358496181195

and i want to it to move 8 metres directly towards north, and 2 metres directly towards east.

Would the new longitude and latitude look like:

current longitude + 0.00008 , current latitude + 0.00002

Heres some of my code to calculate the gradient and the new location:

public double[] calculateXYLength(double[] vals, double distance)
{
    double x = vals[0];
    double y = vals[1];

    if (vals[0] < 0)
        {
            x = x * -1;
        }
    if (vals[1] < 0)
        {
            y = y * -1;
        }
    // Log.d("lengths", "K = " + distance + " / (" + x + " + " + y + " )" );
    double k = distance / (x + y);

    // Log.d("lengths", "vals[0]: " + vals[0] + "  vals[1]: " + vals[1]);
    // Log.d("lengths", "x: " + (vals[0] * k) + "  y: " + (vals[1] * k) +
    // "  k: " + k);
    return new double[] { (vals[0] * k), (vals[1] * k) };
}

Notice the vals is the gradient i already calculated, and the result i'm returning i'm going to use to add to my new location point.

    Location newPosition = currentPosition
    newPosition.setLongitude(myPosition.getLongitude() + val[0]);
    newPosition.setLatitude(myPosition.getLatitude() + val[1]);

But the thing is, I don't get the desired distance between these two locations.. And I can't figure out why. How do I add the desired distance on the latitude/longitude?

Thanks, Johan

Solution found here: stackoverflow.com/questions/2187657/… — leu2tm

ƒernando Valle ƒernando Valle · Accepted Answer · 2012-12-04T13:35:39

The measures of longitude and latitude are degrees not meters, I think that is the problem. 1 degree = 111.12 km

Setting locations latitude & longitude in facing direction

1 Answers