[postgis-users] Re: Initial SRS and geometry columms table creation

[Patrick]

"Ivan Kautter" <ivankautter at hotmail.com> wrote in message 
news:BAY106-F190AFD4ED9D81CD3281610B7380 at phx.gbl...
>
> Lastly, I have a spatial reference system that is not defined in EPSG.  It 
> is a system for the entire state of California in NAD83 defined thusly:
>
>  # California ALBERS projection information
>  PROJECTION
>    "proj=aea"
>    "y_0=-4000000.0"
>    "lon_0=-120.0"
>    "lat_0=0.0"
>    "lat_1=34.0"
>    "lat_2=40.5"
>    "units=m"
>    "ellps=GRS80"
>    "datum=NAD83"
>

Hi Ivan,

This srs IS defined in EPSG and has coord_ref_sys_code (= srid) 3310. It is 
just not in the PostGIS spatial_ref_sys table, probably because the 
proj4text is not defined for some reason (Frank?). SRID, AUTH_NAME and 
AUTH_SRID should thus be 3310, EPSG, and 3310, respectively. The proj4text 
should be (off the top of my head, check on remotesensing.org/geotiff) 
+proj=aea +lat_0=0.0 +lat_1=34.0 +lat_2=40.5 +lon_0=-120.0 +x_0=0 
+y_0=-4000000.

I have created a little bundle of scripts that implement spatial_ref_sys (an 
OGC requirement) as a view from the original EPSG tables. This allows for 
much more options in querying and building new CRSs. Not yet complete, but 
already quite useful. I found the above info using the query:

select * from spatial_ref_sys where srid in (select 
srid_by_placename('United States (USA) - Cal%'));

which gave me 34 CRSs, of which only one matched your parameters.

These scripts can be downloaded from 
http://sourceforge.net/project/showfiles.php?group_id=75000&package_id=168409.

Best regards,
Patrick