customizing epsg codes

[Ed McNierney]

Sebastian -

The WMS specification does not permit the arbitrary creation of new
namespaces for projection codes/indices.  That's why the other posters have
suggested the technique of "inventing" new EPSG codes by editing your epsg
definitions file.

The WMS 1.1.1 specification permits the use of SRS values prefixed with the
AUTO: and EPSG: namespaces only (as well as SRS=NONE).  The server you're
connecting to is violating the spec if they are inventing and publishing new
namespaces.  Under some circumstances I am as willing to bend the rules as
anyone else, but if you are going to require a non-standard behavior of your
clients that will make it very difficult for client software to use your WMS
server.

The most practical and expedient solution is for your client AND the server
to insert those same definitions into the EPSG table so you can make the
request in a manner that's compliant with the WMS specification.  Good luck!

     - Ed
  
-- 
Ed McNierney
Chief Mapmaker
Demand Media / TopoZone.com
73 Princeton Street, Suite 305
North Chelmsford, MA  01863
Phone: (978) 251-4242
Fax: (978) 251-1396
ed at topozone.com


> From: Sebastian Walter <sebastian.walter at FU-BERLIN.DE>
> Reply-To: Sebastian Walter <sebastian.walter at FU-BERLIN.DE>
> Date: Wed, 15 Aug 2007 18:44:27 +0200
> To: <MAPSERVER-USERS at LISTS.UMN.EDU>
> Subject: Re: [UMN_MAPSERVER-USERS] customizing epsg codes
> 
> Thanks for your help. The problem here is that the WMS server I want to
> connect to expects me to ask for the IAU200:49xxx code, which my
> mapserver client doesn't let me sent.
> 
> 
> Gregor Mosheh wrote:
>>> msBuildWMSLayerURL(): WMS connection error. Layer must have an EPSG or
>>> AUTO projection code (in its PROJECTION object or wms_srs metadata)
>>> Can't I include the IAU2000 codes somewhere in my proj setup?
>> 
>> You sure can.
>> 
>> Pop open the "epsg" file in your PROJ installation, e.g.
>> /usr/share/proj/epsg
>> 
>> Add a new record containing your projection's setting and your choice
>> of EPSG code. EPSG codes above 1000000 are reserved for this sort of
>> thing.
>> 
>> Then use the projection as usual:
>> PROJECTION
>>   "init=epsg:1234567"
>> END
>>