android - how can I get the bearing degree between two locations?

Question

As title said, I have current location, and want to know the bearing in degree from my current location to other location. I have read this post, is the value return by location.getBearing() my answer?

Let say it simply: from the picture, I expect the value of 45 degree. foo

What does the documentation for that method tell you? This question is impossible to answers since you have not said why you think this `getBearing()` is **not** the right method. — Simon, Jan 11 '14 at 09:59

score 4 · Answer 1 · edited Jul 10 '19 at 06:21

I was having trouble doing this and managed to figure it out converting the C? approach to working out the bearing degree.

I worked this out using 4 coordinate points

Start Latitude

Start Longitude

End Latitude

End Longitude

Here's the code:

    protected double bearing(double startLat, double startLng, double endLat, double endLng){
    double latitude1 = Math.toRadians(startLat);
    double latitude2 = Math.toRadians(endLat);
    double longDiff= Math.toRadians(endLng - startLng);
    double y= Math.sin(longDiff)*Math.cos(latitude2);
    double x=Math.cos(latitude1)*Math.sin(latitude2)-Math.sin(latitude1)*Math.cos(latitude2)*Math.cos(longDiff);

    return (Math.toDegrees(Math.atan2(y, x))+360)%360;
}

Just change the variable names were needed.

Output bearing to a TextView

Hope it helped!

I have tried the same but I am getting a 90 degree offset, I have given same location for start and end which should give me 0 degrees, I also tried a location in 180 degree but same result — ateebahmed, Oct 28 '18 at 13:27

score 3 · Answer 2 · answered Jan 19 '15 at 14:21

3

Location have method bearingTo: float bearingTo(Location dest)

Location from = new Location(LocationManager.GPS_PROVIDER);
Location to = new Location(LocationManager.GPS_PROVIDER);
from.setLatitude(0);
from.setLongitude(0);
to.setLongitude(10);
to.setLatitude(10);

float bearingTo = from.bearingTo(to);

answered Jan 19 '15 at 14:21

Vladimir

31
1

This method is giving me 90 degree offset on same location and location having 180 degree bearing – ateebahmed Oct 28 '18 at 13:29

score 2 · Answer 3 · edited May 16 '18 at 06:16

Here is the code for calculating bearing angle between two points(startPoint, endPoint):

public float CalculateBearingAngle(double startLatitude,double startLongitude, double endLatitude, double endLongitude){
    double Phi1 = Math.toRadians(startLatitude);
    double Phi2 = Math.toRadians(endLatitude);
    double DeltaLambda = Math.toRadians(endLongitude - startLongitude);

    double Theta = atan2((sin(DeltaLambda)*cos(Phi2)) , (cos(Phi1)*sin(Phi2) - sin(Phi1)*cos(Phi2)*cos(DeltaLambda)));
    return (float)Math.toDegrees(Theta);
}

Call for function:

float angle = CalculateBearingAngle(startLatitude, startLongitude, endLatitude, endLongitude);

score 0 · Answer 4 · answered Jun 27 '22 at 10:01

I found best method for calculating "Bearing between two point " from this answer and convert it to java from python. And this method work like charm for me!

here is the code:

    public static double getBearing(double startLat, double startLng, double endLat, double endLng) {

    double latitude1 = Math.toRadians(startLat);
    double longitude1 = Math.toRadians(-startLng);
    double latitude2 = Math.toRadians(endLat);
    double longitude2 = Math.toRadians(-endLng);

    double dLong = longitude2 - longitude1;

    double dPhi = Math.log(Math.tan(latitude2 / 2.0 + Math.PI / 4.0) / Math.tan(latitude1 / 2.0 + Math.PI / 4.0));
    if (abs(dLong) > Math.PI)
        if (dLong > 0.0)
            dLong = -(2.0 * Math.PI - dLong);
        else
            dLong = (2.0 * Math.PI + dLong);

   return  (Math.toDegrees(Math.atan2(dLong, dPhi)) + 360.0) % 360.0;
}

android - how can I get the bearing degree between two locations?

4 Answers4