The DefaultEllipsoid.orthodromicDistance method has the following problems:
- Could have a better name.
- It does not converge in some situations.
- The wraparound over some non-convergence problems is itself erroneous.
Charles Karney kindly listed the problems on the developer mailing list. A possible action would be to deprecate orthodromicDistance, to be replaced by the same GeodeticCalculator (or any other name) class than the one proposed for
Historical note: orthodromicDistance was defined in the DefaultEllipsoid class because it made easy to override the method with code optimized for the spherical case. A future version could also override the method with code for triaxial ellipsoid. But experience in the Geotk project suggest that this method is almost never used, since GeodeticCalculator is used instead.
As an alternative to deprecate DefaultEllipsoid.orthodromicDistance, we could keep it (after renaming), fix the issues identified by Charles, and design GeodeticCalculator as a class that use DefaultEllipsoid under the hood instead than re-implementing its own algorithm.