地理圆到矩形坐标 [英] Geo circle to rectangle coordinates

问题描述

鉴于输入，中心纬度，中心经度和半径(以公里为单位)，我想获取包含该圆的矩形的坐标(东北和西南纬度/经度).

Given the input, center latitude, center longitude and radius in kilometers, I want to get the coordinates for the rectangle that contains this circle (northeast and southwest lat/lng).

我应该自己编写方法吗?尽管我担心数学有些生疏，但我还是担心不去解释某些事情.还是可以找到适用于Java的现成实现?我的项目中有google maps sdk，但在那里找不到任何有用的东西.

Should I write the method myself? Even though I'm afraid not to account for some things as my math is rusty. Or can I find a ready implementation for java? I have google maps sdk in my project but I couldn't find anything useful there.

推荐答案

我认为您的平方半径比地球半径(6371 km)小得多 这样您就可以安全地忽略地球的曲率.

I suppose your square radius is much smaller than the earth's radius (6371 km) so that you can safely ignore the earth's curvature.

那数学很简单:

// center of square
double latitudeCenter = ...;     // in degrees
double longitudeCenter = ...;    // in degrees

double radius = ...;             // in km
double RADIUS_EARTH = 6371;      // in km

// north-east corner of square
double latitudeNE  = latitudeCenter  + Math.toDegrees(radius / RADIUS_EARTH);
double longitudeNE = longitudeCenter + Math.toDegrees(radius / RADIUS_EARTH / Math.cos(Math.toRadians(latitudeCenter)));

// south-west corner of square
double latitudeSW  = latitudeCenter  - Math.toDegrees(radius / RADIUS_EARTH);
double longitudeSW = longitudeCenter - Math.toDegrees(radius / RADIUS_EARTH / Math.cos(Math.toRadians(latitudeCenter))); 

示例:

中心(lat，lon)在48.00,11.00和半径10 km
将在48.09,11.13给出NE-corner(lat，lon)，在47.91,10.87给出SW-corner(lat，lon).

Center(lat,lon) at 48.00,11.00 and radius 10 km
will give NE-corner(lat,lon) at 48.09,11.13 and SW-corner(lat,lon) at 47.91,10.87.

这是使用 <google-maps-services-java API的c5> :

And here is how to do it with LatLng and Bounds of the google-maps-services-java API:

public static final double RADIUS_EARTH = 6371;

public static Bounds boundsOfCircle(LatLng center, double radius) {
    Bounds bounds = new Bounds();
    double deltaLat = Math.toDegrees(radius / RADIUS_EARTH);
    double deltaLng = Math.toDegrees(radius / RADIUS_EARTH / Math.cos(Math.toRadians(center.lat)));
    bounds.northeast = new LatLng(center.lat + deltaLat, center.lng + deltaLng);
    bounds.southwest = new LatLng(center.lat - deltaLat, center.lng - deltaLng);
    return bounds;
}

这篇关于地理圆到矩形坐标的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！