Martin Desruisseaux ha scritto: > Andrea Aime a écrit : >> I get a good result by using the attached class plus the following >> wkt definiton: >> 100003=(...snip...)SPHEROID["WGS_1984", 6378137.0, 298.257223563]], >> The attached class seems to do the trick, thought it would >> be probably much more compact if Mercator1SP could be extended >> and had a param to force the sphere version of the transform. > > > If we want a sphere, why not setting the "inverse flattening factory" to > 0, as suggested in WKT specification? (not sure where I read that, this > is just a vague souvenir): > > SPHEROID["WGS_1984", 6378137.0, 0.0] > > should work with the ordinary Mercator1SP. The referencing module should > select automatically the sphere version of the transform without the > need for a special "Mercator google" projection.
If the original dataset is based on WGS84, then the trasformation would include some compensation for the difference between the original ellipsoid and the destination sphere, or not? The "Google Projection" is made so that you have to ignore them, see: http://www.spatialreference.org/ref/user/google-projection/ Afaik, this is the meaning of the "[EMAIL PROTECTED]" param in proj. See also: http://proj.maptools.org/faq.html#sphere_as_wgs84 Cheers Andrea ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ Geotools-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/geotools-devel
