Its not in there. The closest in there is SRID=3395 which is just mercator.
+proj=merc +lon_0=0 +k=1.000000 +x_0=0 +y_0=0 +ellps=WGS84 +datum=WGS84 +units=m +no_defs I'm not clear the differences. I suppose we should add it since for example looking at the OpenLayers list - a lot of people use it and it seems to be a defacto id if not an official EPSG code. though whether to use 900913 or 3785. Neither of which are in the spatial_ref_sys to my knowledge. I think Google Mercator does go by multiple SRIDs, so maybe its not really in the standard yet. I'm actually not quite sure about that. Here are a couple of threads http://crschmidt.net/blog/243/google-projection-900913/ http://lists.gpsdrivers.org/pipermail/gpsdrive/2008-March/000855.html According to this the agreed standard is EPSG:3785 but never heard of anyone using that SRID. Most of the examples I have seen use 900913 so maybe the new 3785 is to cover both Virtual Earth and Google but not sure if that quite describes both to the letter. http://www.sharpgis.net/post/2008/05/SphericalWeb-Mercator-EPSG-code-378 5.aspx Hope that helps, Regina -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Pedro Doria Meunier Sent: Wednesday, November 26, 2008 9:11 AM To: PostGIS Users Discussion Subject: Re: [postgis-users] degree vs. metric projection performance? Hi Regina :) Could you please provide the entry for the spatial_ref_sys table for this SRID ? Best regards, Pedro Doria Meunier Obe, Regina wrote: >> By the way, are the Google Mercator and WGS84 systems equivalent >> > > No they aren't. I think Google is a mercator meter projection (not good > for measurement though but more or less good for presentation) and they > use WGS84 datum when accepting data. I think it actually has an > official SRID (could be wrong) > that is EPSG:900913 > > and proj4 looks like this > > +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 [EMAIL PROTECTED] +no_defs > > People usually plot WGS84 longlat (4326) on Google Maps, thus the > confusion. > > _______________________________________________ > postgis-users mailing list > [email protected] > http://postgis.refractions.net/mailman/listinfo/postgis-users > ----------------------------------------- > The substance of this message, including any attachments, may be > confidential, legally privileged and/or exempt from disclosure > pursuant to Massachusetts law. It is intended > solely for the addressee. If you received this in error, please > contact the sender and delete the material from any computer. > _______________________________________________ > postgis-users mailing list > [email protected] > http://postgis.refractions.net/mailman/listinfo/postgis-users > > _______________________________________________ postgis-users mailing list [email protected] http://postgis.refractions.net/mailman/listinfo/postgis-users _______________________________________________ postgis-users mailing list [email protected] http://postgis.refractions.net/mailman/listinfo/postgis-users
