mysql - 将度数转换为其他测量单位

Question

我在 Mysql 服务器中存储一个点作为纬度和经度。他们都是float(10,6)。给定一个半径，比如 100 码或 100 米，我如何计算中心周围的点。我正在考虑使用 GIS，但我听说它不完整或功能非常有限。

Answer 1

1) Tranform the lat/lon to a cartesian based coordinate system of units meter,
the tranformed point is now at (x,y)
2) Use school mathemathics (polar coordinates) to calculate the points:

2a) create points on circle at (0,0) with polar coordinates (r* sin (phi), r* cos(phi)), r in meters, phi in radians 2b) add (x,y) to all that resulting points, to move the circle points from center (0,0) to (x,y)

3) tranform all points back to lat/lon