[Geomoose-users] Google layers, Web Mercator and Coordinates shift

[Brent Fraser]

The great thing about the EPSG system is that you can add coordinate system 
definitions as you need them.

You can use the OpenLayer's code for Spherical Mercator and add it to your 
proj/nad/epsg file:
# Google / OpenLayers
<900913> +proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0 
+k=1.0 +units=m +nadgrids=@null +no_defs


Or you can wait for the various software groups to get updated to the new EPSG 
definitions which include the "official" code of 3785.

Here are some links for more info:
http://www.sharpgis.net/post/2008/05/SphericalWeb-Mercator-EPSG-code-3785.aspx
http://spatialreference.org/ref/sr-org/6/
http://docs.openlayers.org/library/spherical_mercator.html

Best Regards,
Brent Fraser


FRANZ OKYERE wrote:
> Hi all,
> 
> I have mangaged to display the google layers under my other layers fine 
> but it seems there is a shift. I guess, naturally, the coordinates used 
> as for the extents and the map layers have to conform to the 'google's 
> projection'. The little reading I have done, and googling around, tells 
> me that google's projection is not standard- i.e. EPSG just decided to 
> add it on their list.
> 
> Does anyone have a work around- say, a way to do the reprojection? What 
> software would you go for and what are the issues? Thanks.
> 
> /Franz Okyere/
> GIS Specialist