OK, that makes sense. So, it works well when installing additional SRS' , you won't mess up your stock spatial_ref_sys.
The use case that I was going after was where a co-worker wanted to know what srid to use when importing data from a shapefile. I was attempting to use spatialreference.org as a reference to confirm what the standard SRID for this SRS in PostGIS was. I guess that this conflict comes up for SRS' that are part of the stock install. Maybe there is a need for another line on the spatialreference.org page for 'PostGIS SRID' ? Of course, if one already has rights to add data to the db, you can just run a simple (if you know the EPSG code): SELECT * FROM public.spatial_ref_sys WHERE auth_name = 'EPSG' AND auth_srid = 26915; David. On Wed, Sep 22, 2010 at 12:19 PM, David William Bitner <bit...@gyttja.org> wrote: > David, > spatialreference.org uses a local SRID with a prepended '9' while > maintaining an auth_srid to match EPSG so as not to step on the toes of the > SRIDs that are already in the spatial_ref_sys table. While a bit ugly, this > is the intended behavior. It uses the '9' because there are no EPSG codes > that begin with a 9 so it is a clear namespace to not overwrite an EPSG code > regardless of what local SRID identifier is given at spatialreference.org. > Clear as mud? > David > > On Wed, Sep 22, 2010 at 11:41 AM, David Fawcett <david.fawc...@gmail.com> > wrote: >> >> A minor issue here, but I am looking for some clarification. >> >> I am seeking the correct PostGIS srid for UTM Z15N NAD83. >> >> If I query spatialreference.org, >> (http://spatialreference.org/ref/epsg/26915/postgis/) I get: >> >> INSERT into spatial_ref_sys (srid, auth_name, auth_srid, proj4text, >> srtext) values ( 926915, 'epsg', 26915, '+proj=utm +zone=15 >> +ellps=GRS80 +datum=NAD83 +units=m +no_defs ', 'PROJCS["NAD83 / UTM >> zone 15N",GEOGCS["NAD83",DATUM["North_American_Datum_1983",SPHEROID["GRS >> >> 1980",6378137,298.257222101,AUTHORITY["EPSG","7019"]],AUTHORITY["EPSG","6269"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.01745329251994328,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4269"]],UNIT["metre",1,AUTHORITY["EPSG","9001"]],PROJECTION["Transverse_Mercator"],PARAMETER["latitude_of_origin",0],PARAMETER["central_meridian",-93],PARAMETER["scale_factor",0.9996],PARAMETER["false_easting",500000],PARAMETER["false_northing",0],AUTHORITY["EPSG","26915"],AXIS["Easting",EAST],AXIS["Northing",NORTH]]'); >> >> >> From a fairly recent of PostGIS, >> >> SELECT srid, auth_name, auth_srid >> FROM public.spatial_ref_sys >> WHERE auth_srid = 26915 >> >> >> I get: 26915 | EPSG | 26915 >> >> >> I am assuming that the definition at spatial ref.org is wrong? >> >> David. >> _______________________________________________ >> postgis-users mailing list >> postgis-users@postgis.refractions.net >> http://postgis.refractions.net/mailman/listinfo/postgis-users > > > > -- > ************************************ > David William Bitner > > _______________________________________________ > postgis-users mailing list > postgis-users@postgis.refractions.net > http://postgis.refractions.net/mailman/listinfo/postgis-users > > _______________________________________________ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users