why is there no spherical solution to the direct geodesy problem? There is!

[Claudio L.]

(12-05-2016 08:29 AM)StephenG1CMZ Wrote:  Does this mean that the direct solution was not solvable until Vincenty? As far as on-line references go, there is no mention of how it was solved.

On a sphere this is quite simple to solve, they probably don't mention it because it's trivial. The main reason it's hard to solve with ellipsoid is because the length of a curve doesn't have an analytic solution for that shape, but it does for spheres (EDIT: it should say "it does for circles" which is what you need to solve the distance on a sphere), just using simple trig. functions.