[Proj] FW: SCAR Antarctic PS projection issue in proj

[Martin Vermeer]

On Thu, Dec 01, 2005 at 09:56:46PM -0500, Norman Vine wrote:
> 
> > -----Original Message-----
> > From: Mark Fahnestock
> > Sent: Thursday, December 01, 2005 5:13 PM
> > To: norman vine
> > Subject: SCAR Antarctic PS projection issue in proj
> > 
> > 
> > Hi Norman,
> > 
> > Here is the detail on the issue I talked to you about regarding  
> > setting up a WCS for the SCAR projection - this projection has an  
> > EPSG identifier, but is not making it in to proj:
> > 
> > This projection is in the EPSG database, but doesn't survive some  
> > translation stage that generates the epsg file in /usr/local/share/proj
> > 
> > 
> > EPSG:3031 is the SCAR Antarctic Polar Stereographic Projection - lat0  
> > -90  lon0 0 lat_ts -71  ellipsoid WGS84 datum WGS84  Units meters -  
> > note that the scale factor is 1.0, because lat_ts is set.  I believe  
> > that for PS projections, the scale factor is used (or is different  
> > than 1.0) only when the latitude of true scale is not used.
> > 
> > # WGS 84 / Antarctic Polar Stereographic
> > # Unable to translate coordinate system into PROJ.4 format.
> > #
> > # WGS 84 / Australian Antarctic Polar Stereographic
> > # Unable to translate coordinate system into PROJ.4 format.


Googling I found the following old (2002) message by Frank Warmerdam:

"Generally this happens when there is more than one approximation available for
a datum (to WGS84) in the EPSG tables, as the auto-translation code can't
decide which to use.  I also doubt that the EPSG to PROJ.4 stuff properly
accounts for non-greenwich prime meridians.

Have you tried preparing a PROJ.4 definition yourself?"

HTH Martin

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