EPSG conversion

[Ed McNierney]

John -

If I can elaborate on Frank's answer just a bit, you can read the
"Coordinate System" as a set of nested definitions, delimited by those
square brackets.  The AUTHORITY for each definition is associated with
it, so SPHEROID[...AUTHORITY["EPSG","7030"]] shows that the "7030" is
enclosed in the SPHEROID definition.

The PROJCS is the Projected Coordinate System (what we informally call
the "projection") and so you'll see that the 32615 AUTHORITY object is
the one associated with that object.

     - Ed

Ed McNierney
President and Chief Mapmaker
TopoZone.com / Maps a la carte, Inc.
73 Princeton Street, Suite 305
North Chelmsford, MA  01863
Phone: +1 (978) 251-4242
Fax: +1 (978) 251-1396
ed at topozone.com 

-----Original Message-----
From: UMN MapServer Users List [mailto:MAPSERVER-USERS at LISTS.UMN.EDU] On
Behalf Of Frank Warmerdam
Sent: Wednesday, January 24, 2007 7:02 PM
To: MAPSERVER-USERS at LISTS.UMN.EDU
Subject: Re: [UMN_MAPSERVER-USERS] EPSG conversion

John Mitchell wrote:
> Hi,
> 
> Below is a gdalinfo dump and I need to know which of the listed EPSG 
> values I should use for:
> LAYER
>     PROJECTION
>         "INIT=EPSG:32615"
>     END
> 
> Multiple EPSG codes are listed below and I am guessing that it is 
> 32615 from AUTHORITY["EPSG","4326"]],

John,

EPSG code 32615 is indeed the one associated with the root PROJCS
object, so that is what should be used.  The others label datums,
spheroids and units.

Best regards,
-- 
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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    | President OSGeo,
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