On Wed, Jan 27, 2010 at 2:22 AM, Bruce Raup <[email protected]> wrote:
> We propose using terms such as > > grid_top_boundary_projected_y > grid_bottom_boundary_projected_y > grid_left_boundary_projected_x > grid_right_boundary_projected_x > > Alternatively, grid corner coordinates could be used. > > What would the impacts of such a change of names in our files be? If > the GeoRef field is also in the file, would it break existing software > for being able to navigate (geolocate) the data? And, would the > community consider the adoption of more universal terms more generally > (i.e. in GDAL itself)? Bruce, I am not really an expert on the GDAL netcdf driver, but I will attempt to respond. First, I think it would be better to just document that the existing tag names (eg. northernmost_northing) should just be interpreted with the new definitions (grid_top_boundary_projected_y) rather than trying to change the actual tag names in order to gain some possibly clarity in less common situations. I have reviewed the GDAL netcdf driver and it seems to look for two things. First a GeoTransform value (which I think is only a GDAL convention). If that is not found it looks for northernmost_northing, etc. I presume these are part of the CF conventions, though I don't know for sure. I do no see any reference to a "GeoRef" tag. So if you make the planned change, and if you do not also provide the GeoTransform then older versions of GDAL would not be able to read the georeferencing of the files. I presume this might also be the case of almost all other software, even if you did support GeoTransform. However, if you do go ahead with this convention, then please file ticket with a small sample file so we can add support for it. Best regards, -- ---------------------------------------+-------------------------------------- I set the clouds in motion - turn up | Frank Warmerdam, [email protected] light and sound - activate the windows | http://pobox.com/~warmerdam and watch the world go round - Rush | Geospatial Programmer for Rent _______________________________________________ gdal-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/gdal-dev
