Codes of Italian reference systems

[Frank Warmerdam]

Diego Magni wrote:
> Dear List,
> 
> I'd like to point out a problem about id codes of Italian spatial 
> reference systems "Monte Mario / Italy zone 1" and "Monte Mario / Italy 
> zone 2", adopted by Proj library.
> How confirmed also by Spatial Reference 
> (http://spatialreference.org/ref/epsg/x/ , x = 3003/3004 , 
> 102091/102092), the definition of those systems within the epsg lookup 
> file of MapServer is given by the ESRI codes 102091 and 102092.
> Instead, the EPSG service identifies them by the codes 3003 and 3004 
> respectively.
> This could be a bit awkward, e.g. when a MapServer-based application 
> loads data from PostGIS, that uses EPSG 3003 and 3004 codes.
> The problem can be solved by a trick, i.e. by duplicating 102091/102092 
> in the lookup file and assigning them the codes 3003 and 3004, not 
> associated to any reference system at the moment.
> But, in my opinion, a compliance with the EPSG codes could be more 
> suitable.
> 
> Is it planned a redefinition of those reference systems for further 
> releases of MapServer?
> In case, will the EPSG codes replace the ESRI codes or will they coexist?

Diego,

I see that EPSG:3003 and EPSG:3004 are defined in the development
version of PROJ's epsg init file.  I'm not sure when they were introduced.

Generally speaking the EPSG and ESRI codes coexist.  But where an EPSG
coordinate system is defined I believe it should be used in preference to
the ESRI number for it.

Best regards,
-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
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