[Openev-discuss] Arc/Info Ascii Grids?

[Frank Warmerdam]

Ben Discoe wrote:
> 
> I recently found a nice source of Canadian DEMs here:
> http://renres.gov.yk.ca/pubs/rrgis/data/data_desc/90m_dem.html
> 
> They are in "Arc ASCII GRID Format", apparently an extremely simple format
> with a ".asc" file extension. Projection info is in a corresponding ".prj"
> file.
> 
> Although the format was easy to read, my own software does not yet handle
> the "Albers Equal Area Conic" projection. I'm considering switching to GDAL
> for all my projection needs, so i was trying OpenEV today to see if it could
> load the files.
> 
> I discovered that "Arc ASCII GRID" is not on the list of supported formats.
> 
> Could GDAL/OpenEV add support for it?

Ben, 

I have added read-only support for Arc/Info ascii grid files. Is that
sufficient? There are limitations in the .prj support (originating in
gdal/ogr/ogr_srs_esri.cpp, but I am willing to improve if it you give me
problematic .prj files. It does work with albers. 

I was impressed with the software and other material available at VTerrain.org
and I hope you will keep make further suggestions for cooperation and 
cross-fertilization. 

Note that GDAL itself isn't a projections tool. The OGRSpatialReference and
related C++ classes are loosely part of GDAL and are used for manipulating
projections using a normalized from based on OpenGIS Well Known Text format.
The PROJ.4 library is used for underlying reprojection of locations.

Best regards,

---------------------------------------+--------------------------------------
I set the clouds in motion - turn up | Frank Warmerdam, warmerdam at p...
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