[postgis-users] degree vs. metric projection performance?

[Obe, Regina]

>  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 +nadgrids=@null +no_defs

People usually plot WGS84 longlat (4326) on Google Maps, thus the
confusion.

_______________________________________________
postgis-users mailing list
postgis-users at postgis.refractions.net
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.