<HTML dir=ltr><HEAD><TITLE>Re: [Proj] Distance calculation</TITLE>
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<DIV dir=ltr><FONT face="Times New Roman" color=#000000 size=2>It was Thaddeus Vincenty, not Thomas.</FONT></DIV>
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<DIV dir=ltr><FONT size=2>The "exact" solution was published by Dr. Michael E. Pittman in <EM>Surveying and Mapping</EM> in the early 1980s with Fortran code. Vincenty agreed it was more accurate and pointed out a couple singularities that Pittman later fixed. Pittman's geodesic was adopted by the USAF as the absolute "standard" in which any disagreement with Pittman's inverse showed what error the other method had.</FONT></DIV>
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<DIV dir=ltr><FONT size=2>Pittman's direct and inverse geodesic was later reviewed and extensively examined by academics "down under" earlier this year.</FONT></DIV>
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<DIV dir=ltr><FONT size=2>C. Mugnier</FONT></DIV>
<DIV dir=ltr><FONT size=2>LSU</FONT></DIV></DIV>
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<FONT face=Tahoma size=2><B>From:</B> proj-bounces@lists.maptools.org on behalf of Gerald I. Evenden<BR><B>Sent:</B> Tue 14-Oct-08 15:14<BR><B>To:</B> proj@lists.maptools.org<BR><B>Subject:</B> Re: [Proj] Distance calculation<BR></FONT><BR></DIV>
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<P><FONT size=2>On Tuesday 14 October 2008 4:04:48 pm Karl Swartz wrote:<BR>> > Zhang Xue-Lian (1985) The nested coefficient method for accurate<BR>> > solutions of direct and inverse geodetic problems with any length.<BR>> > Proceedings of the 7th International Symposium on Geodetic<BR>> > Computations, Direct and inverse distance<BR>> > functions. Cracow, June 18-21, 1985. Institute of<BR>> > Geodesy and Cartography. Wasaw, Poland, ul. Jasna 2/4 pp 747-763<BR>> ><BR>> > since it's more accurate than the classical method due to Gauss for<BR>> > long distances.<BR>><BR>> How does this compare to Thomas Vincenty's algorithm (which can be found<BR>> at <A href="http://www.ngs.noaa.gov/PUBS_LIB/inverse.pdf">http://www.ngs.noaa.gov/PUBS_LIB/inverse.pdf</A>)?<BR>><BR>> -- Karl<BR><BR>I second the request as I considered it the gold standard and besides full<BR>documentation and source code are available at NGS as well as online<BR>computational services.<BR><BR>--<BR>The whole religious complexion of the modern world is due<BR>to the absence from Jerusalem of a lunatic asylum.<BR>-- Havelock Ellis (1859-1939) British psychologist<BR>_______________________________________________<BR>Proj mailing list<BR>Proj@lists.maptools.org<BR><A href="http://lists.maptools.org/mailman/listinfo/proj">http://lists.maptools.org/mailman/listinfo/proj</A><BR></FONT></P></DIV></BODY></HTML>