>In one of the subprojects of our current project, we get some >coordinates for objects from a network feed, in "UTM projected using >ED50 based on international 1924 spheroid, on zone 32". We'd need to use >those to position objects in a given world space, and I was wondering if >there was a general way to convert such values to something that we can >use in OSG. this transformation is supported by PROJ4, for discrete coordinates, and by gdal (gdalwarp) for raster data using PROJ4. both are available at maptools.org >I suspect values such as "Easting" and "Northing" are not really linear, >since they map to a sphere UTM zones are 6 degrees on longitude wide, with the design goal being a scale error of 1 part in 10000 at the edges. Depending on how big your area is, I doubt that the non-linearity of the projection will be an issue. If you're combining this with other data and want to be precise, you should determine the geographic datum (and vertical datum) of the other data sets. The most common these days is WGS84, used for GPS, with elevations referenced to the ellipsoid or to the geoid. chris
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