本人收集的关于GPS经纬度到直线距离结算公式，求GPS两点夹角以及轴向角的数学理论及示意图。-I collect GPS latitude and longitude to the straight-line distance on the settlement formula, find the angle between the GPS points and the axial angle and schematic diagram of the mathematical theory.

GPS点之间的距离 点到直线的距离 计算两个经纬度之间的距离 计算点c与线段ab的关系数据，采用向量点积的方法(Distance between GPS points Distance from point to line)