Version 2.6 of the C++ library GeographicLib https://geographiclib.sourceforge.io/C++/2.6/index.html
offers some capabilities for dealing with triaxial ellipsoids which may be of interest: * Triaxial::Geodesic3 A treatment of the direct geodesic problem using the solution given by Jacobi (1839) and Liouville (1844). The inverse problem is solved by generalizing the method I used for biaxial ellipsoids. * Triaxial::Conformal3 An implementation of Jacobi's conformal projection (1842-1843). This maps lines of constant (ellipsoidal) latitude and longitude into straight lines and so is the natural generalization of the Mercator projection. A byproduct is the ability to conformally map a triaxial ellipsoid onto a sphere and thence onto any other ellipsoid. * Triaxial::Cartesian3 Methods for transforming between various triaxial coordinates (cartesian to geodetic, etc.). I am 3/4 the way through the paper detailing the geodesic problem. A writeup of the conformal projection will follow. -- Charles Karney <[email protected]> _______________________________________________ PROJ mailing list [email protected] https://lists.osgeo.org/mailman/listinfo/proj
