19

我从http://www.movable-type.co.uk/scripts/latlong.html实施了“轴承”公式。但这似乎非常不准确 - 我怀疑我的实施中有一些错误。你能帮我找到它吗？我的代码如下：

protected static double bearing(double lat1, double lon1, double lat2, double lon2){

double longDiff= lon2-lon1;
double y = Math.sin(longDiff)*Math.cos(lat2);
double x = Math.cos(lat1)*Math.sin(lat2)-Math.sin(lat1)*Math.cos(lat2)*Math.cos(longDiff);

return Math.toDegrees((Math.atan2(y, x))+360)%360;
}
4

4 回答 4

56

这是最终代码：

protected static double bearing(double lat1, double lon1, double lat2, double lon2){
  double longitude1 = lon1;
  double longitude2 = lon2;
  double latitude1 = Math.toRadians(lat1);
  double latitude2 = Math.toRadians(lat2);
  double longDiff= Math.toRadians(longitude2-longitude1);
  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;
}
于 2012-02-27T09:34:29.303 回答
18

你只是把括号()放在错误的地方。

您正在为弧度值添加度数，这是行不通的。toDegrees()将为您进行从弧度到度的转换，然后在您获得度值后进行归一化。

你有：

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

但是你需要：

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

还要记住 的所有输入Math.sin()以及Math.cos()所有其他三角函数必须以弧度表示。如果您的输入是度数，您需要先使用它们进行转换Math.toRadians()。

于 2012-02-26T22:52:18.850 回答
8

从一个坐标到另一个坐标并找到北，东，南，西:)在此处输入图像描述

     public class FindBearing {
            public static void main(String[] args) {
                System.out.println(" Your Result >>> "+FindBearing.bearing(19.2859590, 73.4966430, 19.2861020, 73.4988090));    
            }   
            protected static String bearing(double lat1, double lon1, double lat2, double lon2){
          double longitude1 = lon1;
          double longitude2 = lon2;
          double latitude1 = Math.toRadians(lat1);
          double latitude2 = Math.toRadians(lat2);
          double longDiff= Math.toRadians(longitude2-longitude1);
          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);
          double resultDegree= (Math.toDegrees(Math.atan2(y, x))+360)%360;
          String coordNames[] = {"N","NNE", "NE","ENE","E", "ESE","SE","SSE", "S","SSW", "SW","WSW", "W","WNW", "NW","NNW", "N"};
          double directionid = Math.round(resultDegree / 22.5); 
          // no of array contain 360/16=22.5
          if (directionid < 0) {
              directionid = directionid + 16;
               //no. of contains in array
          }
          String compasLoc=coordNames[(int) directionid];

          return resultDegree+" "+compasLoc;
        }
            }
于 2015-04-06T12:15:31.563 回答
2

@IvanT 答案的一点清理版本：

public static double bearingInRadians(LatLng src, LatLng dst) {
    double srcLat = Math.toRadians(src.getLatitude());
    double dstLat = Math.toRadians(dst.getLatitude());
    double dLng = Math.toRadians(dst.getLongitude() - src.getLongitude());

    return Math.atan2(Math.sin(dLng) * Math.cos(dstLat),
            Math.cos(srcLat) * Math.sin(dstLat) - 
              Math.sin(srcLat) * Math.cos(dstLat) * Math.cos(dLng));
}

public static double bearingInDegrees(LatLng src, LatLng dst) {
    return Math.toDegrees((bearingInRadians(src, dst) + Math.PI) % Math.PI);
}

在哪里LatLng：

public final class LatLng {
    private final double latitude;
    private final double longitude;

    public LatLng(double latitude, double longitude) {
        this.latitude = latitude;
        this.longitude = longitude;
    }

    public double getLatitude() {
        return latitude;
    }

    public double getLongitude() {
        return longitude;
    }
}
于 2016-09-23T13:21:09.633 回答