Coord reprojection real bad

15820
Reporter: mdoering
Type: Bug
Summary: Coord reprojection real bad
Priority: Major
Status: Open
Created: 2014-06-03 17:02:14.237
Updated: 2015-03-02 16:27:04.704
        
        
Description: Check the spherical mercator EPSG:3857 datum transformation in unit tests. Sth goes very wrong here. It is supposed to be nearly the same as WGS84.

http://developer.tomtom.com/docs/read/map_toolkit/javascript_sdk_2_0/Migration_Guide
http://docs.geotools.org/stable/userguide/library/referencing/crs.html#google-maps
http://www.iter.dk/post/2008/05/SphericalWeb-Mercator-EPSG-code-3785.aspx
http://trac.osgeo.org/openlayers/wiki/SphericalMercator
https://trac.osgeo.org/gdal/ticket/3962

There definitely seems to be a mess in those mercator EPSG codes]]>
    

Author: mdoering@gbif.org
Created: 2014-06-04 22:10:39.327
Updated: 2014-06-04 22:10:39.327
        
Mazbe the mercator coordinates should not be in decimal degrees but in meters?
This conversion looks suspicous:
(from http://developer.tomtom.com/docs/read/map_toolkit/javascript_sdk_2_0/Migration_Guide)

\\To transform from EPSG3857 to EPSG4326, it takes a little more work:
var point = new L.Point(-9244844.707434637, 5210979.837890326);
var earthRadius = 6378137;
var latlng = L.Projection.SphericalMercator.unproject(point.divideBy(earthRadius));