An ellipsoid can be specified parametrically by x | = | a cos u sin v y | = | b sin u sin v z | = | c cos v. The geodesic parameters are then P | = | sin^2 v(b^2 cos^2 u + a^2 sin^2 u) Q | = | 1/4(b^2 - a^2) sin(2u) sin(2v) R | = | cos^2 v(a^2 cos^2 u + b^2 sin^2 u) + c^2 sin^2 v.

great circle | oblate spheroid geodesic