[gdal-dev] parsing of netcdf4 no-data values in hdf5 reader

[Agram, Piyush S (334D)]

Hi Even,
     Looking into the issue, I think the NETCDF reader does not read datasets located insides groups for Rasters. There are 2 specific parts of the reader that seems to be the issue:

1. If the drivers does not find 2 arrays that are dimensions under root it bails. This would need to be updated if data is organized within groups and there are no dims/vars at the root level.
2. It only looks into the groups when used for reading vectors and when it does it only parses the string types for geometry definitions. This would need to be updated. 

Some related questions to see if anybody is already planning to contribute these capabilities:

1. Update to NETCDF raster driver to look into sub-groups as well? The spec does not seem to talk about this. Assuming they are trying to be backward compatible with formats that did not support groups - is this acceptable?
2. Support for CF conventions in HDF5 reader? NASA/ESRI seem to be happy working with CF-compliant HDF5.

Adding either support will let people use GDAL with xarray etc. 

Piyush