Hello everyone.
I am looking for a simple formula to compute the distance in Km between two points inside the Earth. I do not mean the usual problem between to cities (distance along the surface) but if I have 2 points (long, lat, depth) say:
p1(0, 10, 100)
p2(1, 10, 150)
How can I compute the distance inside the Earth spheroid?
Kind regards.