[postgis-users] EPSG Code Patterns

[Frank Warmerdam]

Thomas Preuth wrote:
> Hello,
> 
> Are there any Patterns in the List of EPSG codes which define a 
> particular Code as a datum coordinate or e.g. a Transverse Mercator?

Thomas,

There used to be specific code ranges for datums, GCS values, PCS values
and so forth.  But that was discontinued somewhere around EPSG 5.x or so
and now things are increasingly mixed up.

I think you will still find all the geodetic datums are in the 6000's.

To determine if a PCS (Projected Coordinate System) is a Transverse Mercator
projection method you really need to lookup the PCS up and follow a couple
steps through the various EPSG tables.

Of course from within PostgreSQL you can presumably do text based matching
on the wkt column to get a list of SRIDs that match some sorts of
characteristics such as being Tranverse Mercator based.

Best regards,
-- 
---------------------------------------+--------------------------------------
I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush    | Geospatial Programmer for Rent