[Gdal-dev] Ogr Mapinfo driver bug for NZ projections based on datum NZGD2000

[Frank Warmerdam]

Jeremy Palmer wrote:
> Hi,
>  
> I've been having trouble creating Mapinfo files with correct coordinate 
> system header information for NZ projections based on NZGD2000. 
> Currently the trunk version of ogr2ogr is creating Mapinfo files with a 
> WGS84 datum (the default) within the coordsys definition when it should 
> not be. I think the reason for this is the OGRSpatialReference datum 
> name does exactly not match any entries in the asDatumInfoList within 
> mitab_spatialref.cpp.
>  
> I have attached a patch that adds the NZGD2000 datum name as currently 
> loaded into the OGRSpatialReference from WKT. This is not a clean 
> solution as it adds a new entry for a datum definition that already 
> exists. But I see this sort of hack has been done in the past so at 
> least it is consistent!

Jeremy,

You should file a ticket on this if you don't want it getting lost, likely
upstream in the MITAB bugzilla.

I've recently introduced an OGRSpatialReference::GetEPSGGeogCS() method
which attempts to do lots of guessing based on names and stuff to relate
a geogcs/datum with a well known epsg geogcs.  I think the best approach
might be to improve logic in this method for NZGD2000, and modify the MITAB
code to make use of this.

Datum recognition is quite a nightmare currently for many gdal and ogr drivers.

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