On 14 April 2017 at 01:56, C Hamilton <[email protected]> wrote: > Thanks for answering. Geographiclib has a good summary of the benefits over > vincinty. > > https://geographiclib.sourceforge.io/html/python/geodesics.html > > The algorithms implemented by this package are given in Karney (2013) and > are based on Bessel (1825) and Helmert (1880); the algorithm for areas is > based on Danielsen (1989). These improve on the work of Vincenty (1975) in > the following respects: > > The results are accurate to round-off for terrestrial ellipsoids (the error > in the distance is less then 15 nanometers, compared to 0.1 mm for > Vincenty). > The solution of the inverse problem is always found. (Vincenty’s method > fails to converge for nearly antipodal points.) > The routines calculate differential and integral properties of a geodesic. > This allows, for example, the area of a geodesic polygon to be computed. >
There's also https://github.com/mapbox/cheap-ruler - potentially this could be faster and more accurate then Vincenty for smaller distance measures... Nyall _______________________________________________ Qgis-developer mailing list [email protected] List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer
