Grid Square Tools网格定位工具
Maidenhead 网格定位系统是火腿通联中交换位置的标准方式。本工具实现网格坐标与经纬度双向换算，并计算两点间的大圆距离与初始方位角，方便 VHF/UHF 通联、卫星过境和远征时快速确定天线指向。
The Maidenhead grid locator is the standard way hams exchange positions. Convert between grid squares and latitude/longitude in both directions, and compute great-circle distance and initial bearing between two points, handy for aiming antennas on VHF/UHF, satellite passes and expeditions.
Convert between Maidenhead locators and coordinates, and measure distance and bearing between two grids — all in your browser.网格坐标与经纬度互转，并计算两点间距离与方位角——全部在浏览器本地完成。
A. Locator to Coordinates网格转经纬度
Invalid locator. Use 4 or 6 characters, e.g. JO22 or JO22DB (letters A–R, digits, letters A–X).网格格式无效，请输入 4 或 6 位，如 JO22 或 JO22DB。
B. Coordinates to Locator经纬度转网格
Invalid coordinates. Latitude must be -90 to 90, longitude -180 to 180.坐标无效：纬度 -90 到 90，经度 -180 到 180。
C. Distance and Bearing距离与方位角
Invalid locator. Both must be valid 4- or 6-character grids.网格无效，两端都必须是有效的 4 或 6 位网格。