There are various examples of how to define an AreaDefinition throughout the documentation and in test files like https://github.com/pytroll/pyresample/blob/master/pyresample/test/test_files/areas.yaml. However, some of these have projection definitions with only a defined (equatorial radius). This is technically incomplete and although it works in PROJ, rasterio/GDAL are a little more strict and will fail. We've run in to this a couple times with Satpy when trying to save geotiffs. We don't get an error throughout resampling and other coordinate transformations, but saving to geotiffs fails.
All area definitions (even in tests) should no longer define only a and should be discouraged as a valid use. Any existing projections should define b so that it equals a which I think is the default in PROJ/pyproj (@snowman2 do you know?).
There are various examples of how to define an AreaDefinition throughout the documentation and in test files like https://github.com/pytroll/pyresample/blob/master/pyresample/test/test_files/areas.yaml. However, some of these have projection definitions with only
adefined (equatorial radius). This is technically incomplete and although it works in PROJ, rasterio/GDAL are a little more strict and will fail. We've run in to this a couple times with Satpy when trying to save geotiffs. We don't get an error throughout resampling and other coordinate transformations, but saving to geotiffs fails.All area definitions (even in tests) should no longer define only
aand should be discouraged as a valid use. Any existing projections should definebso that it equalsawhich I think is the default in PROJ/pyproj (@snowman2 do you know?).