Question

我正在尝试使用一部分代码（类似于我下面的代码），因此OBJECT_LOC和CONVERTED_LOC完全相同。我认为代码对于我正在做的事情非常简单，但由于某种原因它们并不平等？我究竟做错了什么？（您可以在下面看到输出）。

import com.bbn.openmap.LatLonPoint;
import com.bbn.openmap.proj.Length;
import com.bbn.openmap.proj.coords.DMSLatLonPoint;

public class Test {

       /**
        * @param args
        */
       public static void main(String[] args) {

               // 45:20:00.0N/24:00:00.0E
               LatLonPoint BASE_LOC = new DMSLatLonPoint(false, 45, 20, 00.0f, false,
                               24, 00, 00.0f).getLatLonPoint();

               System.out.println("BASE_LOC: " + BASE_LOC);

               LatLonPoint OBJECT_LOC = new LatLonPoint(52.749355, 26.346556);

               System.out.println("OBJECT_LOC: " + OBJECT_LOC);

               float distanceX = BASE_LOC.distance(new LatLonPoint(BASE_LOC
                               .getLatitude(), OBJECT_LOC.getLongitude()));

               float distanceY = BASE_LOC.distance(new LatLonPoint(OBJECT_LOC
                               .getLatitude(), BASE_LOC.getLongitude()));


               LatLonPoint CONVERTED_POINT = new LatLonPoint(BASE_LOC.getLatitude()
                               + Length.DECIMAL_DEGREE.fromRadians(distanceY),
                               BASE_LOC.getLongitude()
                                               + Length.DECIMAL_DEGREE.fromRadians(distanceX));

               System.out.println("CONVERTED_POINT " + CONVERTED_POINT);

       }
}

输出：

BASE_LOC: LatLonPoint[lat=45.333332,lon=24.0]
OBJECT_LOC: LatLonPoint[lat=52.749355,lon=26.346556]
CONVERTED_POINT LatLonPoint[lat=52.749355,lon=25.649527]

Answer 1

在查看API文档和一些关于地理的文献之后，看起来你发现第二点的方法是有缺陷的。正确的方法是使用距离和方位（方位角）。以下是更正后的代码：

import com.bbn.openmap.LatLonPoint;
import com.bbn.openmap.proj.coords.DMSLatLonPoint;

public class TestProgram {

   /**
    * @param args
    */
   public static void main(String[] args) {

           // 45:20:00.0N/24:00:00.0E
           LatLonPoint BASE_LOC = new DMSLatLonPoint(false, 45, 20, 00.0f, false, 24, 00, 00.0f).getLatLonPoint();
           System.out.println("BASE_LOC: " + BASE_LOC);

           LatLonPoint OBJECT_LOC = new LatLonPoint(52.749355, 26.0);
           System.out.println("OBJECT_LOC: " + OBJECT_LOC);

           float distance = BASE_LOC.distance(OBJECT_LOC);
           float az = BASE_LOC.azimuth(OBJECT_LOC);

           LatLonPoint CONVERTED_POINT = BASE_LOC.getPoint(distance, az);

           System.out.println("CONVERTED_POINT " + CONVERTED_POINT);

   }

}

此处提供了一些信息 - http://www.movable-type.co.uk/scripts/latlong.html

Answer 2

当你正在进行BASE_LOC.distance（）调用时，你需要在两个距离的参数中交换OBJECT_LOC / BASE_LOC。 OBJECT_LOC / BASE_LOC在一个，BASE_LOC / OBJECT_LOC在另一个。

Lat / Long和距离的Java问题

2 个答案: