Additional entry of length or number of octets in GRIB2_Template_ csv-files

[SibylleK]

Details

In GRIB2 Template definition files the octet number (from - to) for each entry in the GRIB section is given.
Most of the GRIB processing software packages need the length or number of octets for each entry, which has to be calculated from the specification of "OctetNo".

But with variables and repitition within some templates an automated calculation is sometimes not easy. (e.g. 37 + (ND-1)*4 + (NF-1)*4 -40 +(ND-1)*4 + (NF-1)*4)

Therefore, this is a proposal to add a column with the length of each entry in the GRIB2_Template files.

Requestor

Sibylle Krebber, @SibylleK

[shahramn]

A very good suggestion

[amilan17]

https://github.com/wmo-im/CCT/wiki/20.to.22.September.2023 notes:

• Title_en, OctetNo, octetCount, Contents_en, Note_en, noteIDs, codeTable, flagTable, Status
• there could be an impact on the software that is ingesting the machine-readable codes; 
• the script to generate the TXT,CSV will need to be updated
• template with a sample and the software can be updated for testing

[antoinemerle]

@antoinemerle :
On roadmap purpose and planning on EUM side :

• : need to check in the vocabulary manager what would be the impact : are we taking the data from the xml or note, how do we parse the xml in a way it is going to break or not our interfaces.
• Estimate the cost of the impact on EUM side / implementation of this new colomn

e.g :

[sebvi]

Are we implementing this? I don't see a branch created for it

[marijanacrepulja]

I believe we agreed to address this after finalising FT2024-1.

[amilan17]

https://github.com/wmo-im/tt-tdcf/wiki/2024.10.15.tt.tdcf notes:
@amilan17 will update master after merging in FT2024-2 branch

[amilan17]

Do the machine-readable files also need to include OctetCount?

[sebvi]

Octet counts are not needed on our side

EDIT: actually it is a useful validation if the count is present

[amilan17]

https://github.com/wmo-im/tt-tdcf/wiki/2024.11.12.tt.tdcf notes:

• empty columns are created for all templates, needs checking
• @antoinemerle can help with scripts to ensure that the TXT and XML output files do NOT include the OctetCount column
• Sibylle it would be even better (eventually) if the octet can be calculated from the OctetCount but not necessary today
• @antoinemerle new script to retroactively populate all octetCount columns