如何计算地理点和给定多边形之间的距离（以米为单位）？

Question

首先，我是GIS新手，如有错误请见谅。我需要发现纬度和经度点与 latitude/longitude 多边形（规则与否）之间的距离。准确地说，我需要发现从给定点到多边形边界中的点的最小距离，如下图所示。在示例中，点 p 到多边形的较近距离是 d。注意：我不需要点，只需要最小距离。

经过一些阅读，我想出了以下使用 GeoTools API 的最小工作示例。但是，我认为我搞砸了输出。谁能启发我如何获得以米为单位的点和多边形之间的最小距离？

MWE.java:

import com.vividsolutions.jts.geom.Coordinate;
import com.vividsolutions.jts.geom.Geometry;
import com.vividsolutions.jts.geom.GeometryFactory;
import com.vividsolutions.jts.geom.Point;

public class MWE {

    public static void main(String[] args) throws Exception {
        GeometryFactory gf = JTSFactoryFinder.getGeometryFactory();

        Coordinate[] c = new Coordinate[5];
        c[0] = new Coordinate(-49.242986, -16.662430);
        c[1] = new Coordinate(-49.241999, -16.664465);
        c[2] = new Coordinate(-49.239146, -16.663828);
        c[3] = new Coordinate(-49.239832, -16.661443);
        c[4] = new Coordinate(-49.242986, -16.662430);

        Geometry geo = gf.createPolygon(c);

        Point p = gf.createPoint(new Coordinate(-49.246870, -16.665493));

        double distance = geo.distance(p);

        System.out.println("Distance: " + distance);

    }
}

Answer 1

所以您所做的是正确的，但它将 return 以大地测量单位（弧度）而不是米为单位的距离。您有两个选择：

将点和多边形几何图形转换为平面参考系http://docs.geotools.org/latest/tutorials/geometry/geometrycrs.html
使用大地测量计算器http://docs.geotools.org/stable/userguide/library/referencing/calculator.html

要使用 GeodeticCalculator，您需要确定多边形边界上离您的点最近的点。例如DistanceOp.closestPoints(geo, p)[0]

// adapted from http://docs.geotools.org/stable/userguide/library/referencing/calculator.html
CoordinateReferenceSystem crs = CRS.decode("EPSG:4326");
GeodeticCalculator gc = new GeodeticCalculator(crs);
gc.setStartingPosition( JTS.toDirectPosition(  DistanceOp.closestPoints(geo, p)[0], crs ) );
gc.setDestinationPosition( JTS.toDirectPosition( p, crs ) );

double distance = gc.getOrthodromicDistance();

如何计算地理点和给定多边形之间的距离（以米为单位）？

How to calculate the distance in meters between a geographic point and a given polygon?

java

gis

geospatial

geotools