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Friday, October 24th, 2008Well, now I know all about geographic datums and projections, and what’s the difference between WGS84, EPSG:4326, EPSG:900913. The answer is that WGS 84 is a datum, EPSG:4326 is a projection which refers to WGS 84, no hang on that’s not right, it’s a datum, the same one WGS 84. Actually I’m not so sure about that. Anyway, EPSG:900913 is the new name for a spherical mercator projection. Or is it a datum, I’m not sure? The important thing is that it approximates the Earth as a sphere instead of an ellipsoid, and this makes some geographers really angry.
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