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Unsupported file structure

Added by Richard Harvey over 1 year ago

Hello,

I got this error message when using cdo on an otherwise perfectly normal grib file:

Error in calling operator remapbil with:

cdo -O -s -remapbil,/vagrant/data/output/MODEL_DATA/sref/20230629/09/cat/stations sref_2t.grib2 series_2t.grib2<<<

STDOUT:
STDERR:Warning (gribapiScanTimestep2): Record 3 (name=2t id=0.0.0 lev1=2 lev2=0) timestep 2: Parameter not defined at timestep 1!
cdo remapbil: Open failed on >sref_2t.grib2<
Unsupported file structure

When I run "file" on the faulty file, I can confirm this is a bonefide grib2:

$ file myfile.grib2

myfile.grib2 : Gridded binary (GRIB) version 2

$

I seem to have come across this on one of the forums in that cdo still has issues with the way certain valid grib2 files are internally structured.

Any ideas, anybody ?

Richard

Download all files
sref_nmb.t09z.pgrb132.n1.f81.grib2 (290 KB) sref_nmb.t09z.pgrb132.n1.f81.grib2 File for which the cdo -infon command works
sref_2t.grib2 (17.5 MB) sref_2t.grib2 File for which the cdo -infon command throws the 'Unsupported file structure' error

Replies (2)

RE: Unsupported file structure - Added by Uwe Schulzweida over 1 year ago

Hello Richard,

The file contains the variable 2t for the data type cf (Control forecast product) and pf (Perturbed forecast product).
It looks like all GRIB records appear twice in the file. This leads to an inconsistency from CDO's point of view even if it is a valid GRIB file.

Here are the first 20 records of the GRIB file:

grib_ls sref_2t.grib2  | head -20
sref_2t.grib2
edition      centre       date         dataType     gridType     stepRange    typeOfLevel  level        shortName    packingType  
2            kwbc         20230629     cf           lambert      3            heightAboveGround  2            2t           grid_simple 
2            kwbc         20230629     cf           lambert      3            heightAboveGround  2            2t           grid_simple 
2            kwbc         20230629     pf           lambert      3            heightAboveGround  2            2t           grid_simple 
2            kwbc         20230629     pf           lambert      3            heightAboveGround  2            2t           grid_simple 
2            kwbc         20230629     pf           lambert      3            heightAboveGround  2            2t           grid_simple 
2            kwbc         20230629     pf           lambert      3            heightAboveGround  2            2t           grid_simple 
2            kwbc         20230629     pf           lambert      3            heightAboveGround  2            2t           grid_simple 
2            kwbc         20230629     pf           lambert      3            heightAboveGround  2            2t           grid_simple 
2            kwbc         20230629     pf           lambert      3            heightAboveGround  2            2t           grid_simple 
2            kwbc         20230629     pf           lambert      3            heightAboveGround  2            2t           grid_simple 
2            kwbc         20230629     pf           lambert      3            heightAboveGround  2            2t           grid_simple 
2            kwbc         20230629     pf           lambert      3            heightAboveGround  2            2t           grid_simple 
2            kwbc         20230629     pf           lambert      3            heightAboveGround  2            2t           grid_simple 
2            kwbc         20230629     pf           lambert      3            heightAboveGround  2            2t           grid_simple 
2            kwbc         20230629     cf           lambert      6            heightAboveGround  2            2t           grid_simple 
2            kwbc         20230629     pf           lambert      6            heightAboveGround  2            2t           grid_simple 
2            kwbc         20230629     pf           lambert      6            heightAboveGround  2            2t           grid_simple 
2            kwbc         20230629     pf           lambert      6            heightAboveGround  2            2t           grid_simple
CDO can work with the data if you split the file into the data type:
grib_copy -w dataType=pf sref_2t.grib2 pf_sref_2t.grib2
grib_copy -w dataType=cf sref_2t.grib2 cf_sref_2t.grib2
Cheers,
Uwe

RE: Unsupported file structure - Added by Richard Harvey over 1 year ago

Thanks Uwe for your quick response!

Just installed the libeccodes-tools library...

Richard

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