pos2dist

Calculate distance between two points on earth's surface given by latitude-longitude pair.

Calculate distance between two points on earth's surface given by their latitude-longitude pair. Choose method 1 or 2. Method 1 uses plane approximation, only for points within several tens of kilometers; Method 2 calculates sphereic geodesic distance for points farther apart, but ignores flattening of the earth. Output is in km.