The great-circledistance calculates the shortest distance between any two points on the surface of a sphere.
大圆弧长计算球面两点之间的最短距离。
2
In other cases, a spherical model is used, and the primary distance calculation used is the great-circledistance (see Resources).
在其他情况下使用球面模型,所使用的主要距离计算为大圆弧长(参见参考资料)。
3
For the purposes of this article, I will demonstrate distances using the flat-Earth model and the great-circledistance and leave the rest to you to explore.