Hello!
I'm writing a program to import GRIB2 files into our data store. As it turns
out, GRIB(2) is strange. As described here (see
150+notes)<http://www.nco.ncep.noaa.gov/pmb/docs/grib2/grib2_table4-5.shtml>
GRIB2 variables may have a "Generalized Vertical Height Coordinate" which is
not part of the coordinate system but described through an external "3D-GRIB
message". Sadly I have exactly that case.
Until now I have not found a way to access this data through the usual netCDF
Java interface. I open the grib2 file as a GridDataset, but as the level is not
part of the variable's coordinates definition it doesn't appear as an axis of
the GridCoordSystems. Reading the data from the value variable only imports the
topmost layer (40-41 in this case). As seen in this
screenshot<http://imgur.com/a/kMnIy> the ToolsUI tool can access it, but only
from the GRIB2 view. The levels neither appear in the NcML dump nor as a
(dimension-)variable. They seem to be part of the GRIB2 PDS section.
My question is: is there a way to access this additional level data through the
common interface? And if not, how can I access the PDS sections? I am not sure
how to open a GRIB2 file with the specialized GRIB2 classes. I am using
NetCDF-4.6.6.
Thanks in advance!
Nikolas
