[Proj] Distance calculations

Irwin Scollar al001 at uni-koeln.de
Wed Oct 15 09:10:25 EDT 2008

Karl Swartz wrote:

How does this compare to Thomas Vincenty's algorithm (which can be found
at http://www.ngs.noaa.gov/PUBS_LIB/inverse.pdf)?

and Gerald Evenden wrote:

I second the request as I considered it the gold standard and besides full
documentation and source code are available at NGS as well as online
computational services.

An on-line source with a derivation of the Zhang Xue-Lian distance 
calculations can be found in


pages 18 ff.

I have not found  on-line sources for the Pittman paper or critiques 
noted by Cliff Mugnier.

It would indeed be helpful if the three methods can be compared for accuracy.

Irwin Scollar

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