Great Circle distance and midpoint betweeen Latitude/Longitude points
This will compute the
great-circle distance between two latitude/longitude points, as well as the middle point.
The script uses Haversine formula, which results in in approximations less than 1%.
Enter either:
decimal latitudes/longitudes with minus sign for South and West
degrees minutes seconds in a format like E 32 14 9 (32°14'9" East longitude).