I am currently trying to compute the real distance between two 3D points (on a WS84 ellipsoid represensation of our earth), but my knowledge in Geographic Information System is pretty nil (except the fact that I know about using geodesic distance instead of the classic sqrt).
What I use can already compute the geodesic distance between two pair of longitude / latitude, it does not however provide the 3D distance.
So I though about using the classic sqrt distance formula using the result of the geodesic distance and the height, is this approach right ?
I can use either the raw mathematica formula, or one that use the current geodesic distance with the difference of elevation.
Note : I obviously tryed to google it, but I only end up on full of article about building 3D mesh using geodesic distance. So I am wondering also if I am really using the right word when searching for "geodesic distance between 3D points".
I checked this from a post given by the tool that suggest question to check but as it seems it ignores the elevation differences : http://www.movable-type.co.uk/scripts/gis-faq-5.1.html