[GRASS-dev] Re: [Gfoss] errore datum...

[Paul Kelly]

On Fri, 30 May 2008, Markus Neteler wrote:

> Hello Paul,
>
> a problem came up in the Italian list:
>
> g.proj -c epsg=23033 loc=llll
> WARNING: Datum <unknown> not recognised by GRASS and no parameters found
> Location llll created!

This is now fixed in SVN trunk. It seems at some stage there were some 
changes to the way GDAL parsed PROJ.4 strings such as "+init=epsg:XXXX" - 
as far as I can see it now attempts to expand the string into a full 
PROJ.4 string before doing a secondary conversion to a WKT-format 
co-ordinate system, and in the process the datum information is lost. I'm 
not sure what the logic for this change is, but anyway I've worked around 
it by changing g.proj to call OSRImportfromEPSG() directly when given the 
epsg= option. However a consequence of this is that the old-style
g.proj -c proj4=init=epsg:XXXX location=newloc
will no longer work properly; you must use
g.proj -c epsg=XXXX location=newloc.

Many thanks to Alfredo Alessandrini for the original bug report. If there 
are no issues I'll backport it to 6.4 later.

Paul