Selon Christopher Barker <chris.bar...@noaa.gov>: I'd note that in the OGR XPlane driver, a function is available to compute the distance on the spheroid. You could use it if you don't need much accuracy : http://trac.osgeo.org/gdal/browser/trunk/gdal/ogr/ogrsf_frmts/xplane/ogr_xplane_geo_utils.cpp
(It's an internal function to OGR, so you'd have to copy&paste it in your code, or add a CPL_DLL decoration in the corresponding .h and rebuild GDAL) > Yilmaz Arslanoglu wrote: > > I wanted to compute the distance between two points, > > you need to be clear by what you mean here: I suspect you mean: > > "The shortest distance between two points following the surface of the > earth" > > In which case, what you are looking for is referred to as the geodesic > distance: > > http://www.vterrain.org/Misc/distance.html > > To do this accurately (and you may not need much accuracy!) on an > ellipsoid requires a fair bit of math. I don't know if it's built in to > OGR or PROJ at this point, but there are a few libraries out that that > do it, including Gerald I. Evenden's "geodesic" lib, which can be found > here: > > http://home.comcast.net/~gevenden56/geodesy/project/ > > -Chris > > > > -- > Christopher Barker, Ph.D. > Oceanographer > > Emergency Response Division > NOAA/NOS/OR&R (206) 526-6959 voice > 7600 Sand Point Way NE (206) 526-6329 fax > Seattle, WA 98115 (206) 526-6317 main reception > > chris.bar...@noaa.gov > _______________________________________________ > gdal-dev mailing list > gdal-dev@lists.osgeo.org > http://lists.osgeo.org/mailman/listinfo/gdal-dev > _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev