On Feb 12, 2011, at 1:59 PM, ext Stefan Keller wrote: > Hi, > > I'm confused about the 'right' coordinate reference system while > having to decide with which srid to take on a geometry (PostGIS). > > When looking at > http://dev.openlayers.org/releases/OpenLayers-2.10/doc/apidocs/files/OpenLayers/Layer/SphericalMercator-js.html > it says "Transforms from EPSG:4326 to EPSG:900913 and from EPSG:900913 > to EPSG:4326 are set by this class." > > * When looking up EPSG:900913 on spatialreference.org it finds nothing. > * There's a link in the doc. to > http://spatialreference.org/ref/sr-org/google-projection/ which > actually indicates SR-ORG:6 (I expected EPSG:900913) > * I read about another EPSG:3785 > (http://spatialreference.org/ref/epsg/3785/) which says "Popular > Visualisation CRS / Mercator" > > 1. Is EPSG:900913 really the one used by Google Maps API and is it up-to-date? > 2. Should someone update spatialreference.org with EPSG:900913 (or is > this a synonym of/equivalent to EPSG:3785 and SR-ORG:6)? > 3. As of now, the doc. shoud explain why > http://spatialreference.org/ref/sr-org/google-projection/ whows > SR-ORG:6 and not EPSG:900913!
EPSG is an official, trademarked name. Putting things into the EPSG namespace -- like we (OpenLayers developers) have done with EPSG:90013 -- does not make them happy. Although OpenLayers is happy to use EPSG:900913, Spatial Reference .org attempts to act as an official repository in the EPSG: namespace, so we do not add 'fake' entries to that dataset. EPSG:3785 was the 'old' EPSG code for what we call EPSG:900913. This was replaced by EPSG:3857, which is the 'new' EPSG code for what we call EPSG:900913. The proj4/WKT from SR-ORG:6 is the right proj4 for EPSG:900913 as we use it in OpenLayers. It seems that all of your problems are with sr.org, not with OpenLayers, so I recommend you take your concerns to the MetaCRS list. If you feel strongly about the OpenLayers doc issue, feel free to submit a patch. -- Chris > Yours, S. > _______________________________________________ > Users mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/openlayers-users _______________________________________________ Users mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/openlayers-users
