Subject: Geodesic software Newsgroups: gmane.comp.gis.proj-4.devel Date: Sunday 7th December 2008 21:18:33 UTC (over 8 years ago) On my website http://members.verizon.net/~gerald.evenden/proj4/ a library of converted NGS Vincenty geodesic procedure and an application program, 'geodesic', are now available in geodesic20081207.tar.bz2. In the case of a spherical earth Snyder's preferred equations are used. The only additional requirement is a libproj4.a library. The program 'geodesic' has a fairly detailed help assistance and the user should be successful without documentation. Just start out with geodesic geod: earth ellps=WGS84 # set elliptical figure geod: p1 20 30 # set base point in arc geod: p2 30 45 # do an inverse projection Point 1 Lon: 20dE Lat: 30dN Point 2 Lon: 30dE Lat: 45dN Azimuth p1->p2: 25d1'34.18757" Distance: 1881597.763 Azimuth p2->p1: 211d10'34.37818" geod: vector 100000 45 # do a forward projection Point 1 Lon: 20dE Lat: 30dN Point 2 Lon: 20d44'15.34034"E Lat: 30d38'8.82286"N Azimuth p1->p2: 45d Distance: 100000.000 Azimuth p2->p1: 225d22'20.44298" geod: circle help # ask for help with arc generation circle azimuth delta_azi computes points along a circular arc centered at arc structure node p1 and extending from arc node p2 in a clockwise direction through an angle define by 'azimuth' and divided by intermediate points at approximately 'az' angular separation. 'circle 360 10' describes a circle of points at 10 degree 'delta_az' interval geod: quit That should give you an idea. It is preliminary and any debug tries and suggestions would be appreciated. All angular input are in the same format used by libproj4 and older pro4x versions. -- The whole religious complexion of the modern world is due to the absence from Jerusalem of a lunatic asylum. -- Havelock Ellis (1859-1939) British psychologist _______________________________________________ Proj mailing list [email protected] http://lists.maptools.org/mailman/listinfo/proj |
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