Calculate angle between two Latitude/Longitude points

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Is there a way to calculate angle between two Latitude/Longitude points?

What I am trying to achieve is to know where the user is heading. For example, user is head

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17条回答

刺人心

2020-12-07 18:34

In The Javascript, I create a function name angleFromCoordinate in which i pass two lat/lng. This function will return angel between that two lat/lng

function angleFromCoordinate(lat1,lon1,lat2,lon2) {
    var p1 = {
        x: lat1,
        y: lon1
    };

    var p2 = {
        x: lat2,
        y: lon2
    };
    // angle in radians
    var angleRadians = Math.atan2(p2.y - p1.y, p2.x - p1.x);
    // angle in degrees
    var angleDeg = Math.atan2(p2.y - p1.y, p2.x - p1.x) * 180 / Math.PI;
    console.log(angleDeg);
    return angleDeg;
}

Working Code Snippet

function angleFromCoordinate(lat1,lon1,lat2,lon2) {
    var p1 = {
        x: lat1,
        y: lon1
    };

    var p2 = {
        x: lat2,
        y: lon2
    };
    // angle in radians
    var angleRadians = Math.atan2(p2.y - p1.y, p2.x - p1.x);
    // angle in degrees
    var angleDeg = Math.atan2(p2.y - p1.y, p2.x - p1.x) * 180 / Math.PI;

    document.getElementById('rotation').innerHTML ="Rotation : "+ angleDeg;
    return angleDeg;
    
}
     angleFromCoordinate(37.330604,-122.028947,37.3322109,-122.0329665);

<html>
<p id="rotation">Rotation : </p>
</html>

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难免孤独

2020-12-07 18:37

function calculateAngle(lat, lng) {
    var checkLengthInterval = 2;

    // Calculate Angle
    //If ObjFeed == [] add first object.
    if (ObjFeed.length == 0) {
        ObjFeed.push({ 'lat': lat, 'lng': lng });
    } else {
        // Get last object from list to calculate angle betwn last and latest.
        var tempNode = ObjFeed[ObjFeed.length - 1];
        // If last lat and lng is same as current it will always return 0 angle.so only push lat lng in obj which is diff than last one.
        if (!(tempNode.lat == lat && tempNode.lng == lng)) {
            ObjFeed.push({ 'lat': lat, 'lng': lng });
        } else {
            console.log('exact match for lat lng');
        }
    }
     // this is for to keep only few objects in the list and remove other
    if (ObjFeed.length >= checkLengthInterval) {
        // calculating angle only if previous data point is available
        ObjFeed = ObjFeed.slice(-1 * checkLengthInterval); // remove all items in array except last two
        var point1 = ObjFeed[ObjFeed.length - checkLengthInterval];
        var point2 = ObjFeed[ObjFeed.length - 1];

        console.log('previous point1', point1);
        console.log('next point2', point2);

        var dLng = (point2.lng - point1.lng);
        var dLat = (point2.lat - point1.lat);

        dLng = dLng * 10000;
        dLat = dLat * 10000;

        var dlat_by_dlan = 0;

        try {
            dlat_by_dlan = dLng / dLat;
        } catch (err) {
            dlat_by_dlan = NaN;
            console.log('Exception: dLat == 0');
        }

        var angleDegreeBearing = 0, angleBearingRad = 0;
        angleBearingRad = Math.atan(dlat_by_dlan);
        angleDegreeBearing = angleBearingRad * 180 / Math.PI;

        if (dLat < 0 && dLng < 0) {
            angleDegreeBearing = angleDegreeBearing + 180;
        } else if (dLat < 0 && dLng > 0) {
            angleDegreeBearing = angleDegreeBearing + 180;
        } else if (dLat == 0 && dLng == 0) {
            angleDegreeBearing = prevVechicleAngle;
        } else if (dlat_by_dlan == NaN) {
            angleDegreeBearing = prevVechicleAngle;
        }

        console.log('angleDegreeBearing', angleDegreeBearing);

    } else {
        // setting up default angle to 0 if previous data point is not available to calculate actual anglle
        console.log('feedArray default angle 0');
        angleDegreeBearing = 0;
    }
    prevVechicleAngle = angleDegreeBearing;
    return angleDegreeBearing;

}

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长发绾君心

2020-12-07 18:38

using this referance to calculate Angle:

private double angleFromCoordinate(double lat1, double long1, double lat2,
        double long2) {

    double dLon = (long2 - long1);

    double y = Math.sin(dLon) * Math.cos(lat2);
    double x = Math.cos(lat1) * Math.sin(lat2) - Math.sin(lat1)
            * Math.cos(lat2) * Math.cos(dLon);

    double brng = Math.atan2(y, x);

    brng = Math.toDegrees(brng);
    brng = (brng + 360) % 360;
    brng = 360 - brng; // count degrees counter-clockwise - remove to make clockwise

    return brng;
}

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挽巷

2020-12-07 18:38

For those who use C/C++, below is the tested code:

static const auto PI = 3.14159265358979323846, diameterOfEarthMeters = 6371.0 * 2 * 1000;

double degreeToRadian (double degree) { return (degree * PI / 180); };
double radianToDegree (double radian) { return (radian * 180 / PI); };

double CoordinatesToAngle (const double latitude1,
                           const double longitude1,
                           const double latitude2,
                           const double longitude2)
{
  const auto longitudeDifferenceRadians = degreeToRadian(longitude2 - longitude1);
  auto latitude1Radian = degreeToRadian(latitude1),
       latitude2Radian = degreeToRadian(latitude2);

  const auto x = std::cos(latitude1Radian) * std::sin(latitude2Radian) -
                 std::sin(latitude1Radian) * std::cos(latitude2Radian) *
                 std::cos(longitudeDifferenceRadians);
  const auto y = std::sin(longitudeDifferenceRadians) * std::cos(latitude2Radian);

  return radianToDegree(std::atan2(y, x));
}

double CoordinatesToMeters (const double latitude1,
                            const double longitude1,
                            const double latitude2,
                            const double longitude2)
{
  auto latitude1Radian = degreeToRadian(latitude1),
       longitude1Radian = degreeToRadian(longitude1),
       latitude2Radian = degreeToRadian(latitude2),
       longitude2Radian = degreeToRadian(longitude2);
  auto x = std::sin((latitude2Radian - latitude1Radian) / 2),
       y = std::sin((longitude2Radian - longitude1Radian) / 2);

  return diameterOfEarthMeters *
         std::asin(std::sqrt((x * x) +
                             (std::cos(latitude1Radian) * std::cos(latitude2Radian) * y * y)));
}

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小蘑菇

2020-12-07 18:38
Make sure its a rhumb line bearing NOT a great circle bearing as the initial bearing changes according to distance
```
 double angle= Math.min((pbearingf-tbearingf) < 0 ? pbearingf-tbearingf+360:pbearingf-tbearingf, (tbearingf-pbearingf)<0?tbearingf-pbearingf+360:tbearingf-pbearingf);
```
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