New parameters in Code Table 4.2 for radar data

[sebvi]

Initial request

For the encoding of Opera and Nimbus radar data in GRIB2, this proposal suggests adding additional code table entries to describe the data quality index and the radar data quality flagThese entries encode essential metadata that enhances data validation, enabling users to assess the accuracy and reliability of precipitation measurements more effectively.

Amendment details

ADD to code table 4.2: Product discipline 0 Meteorological products, parameter category 15: radar

Code	Description	Unit
18	Radar data quality index (see note)	Proportion
19	Radar data quality flag	Code table 4.106

Note: Spatially analyzed quality indicator, according to OPERA II (Holleman I., Michelson D., Galli G., Germann U., and Peura M., 2006: Quality information for radars and radar data. OPERA II deliverable OPERA_2005_19), normalized to between 0 (poorest quality) to 1 (best quality). 

CREATE code table 4.106: Radar data quality flags

Code	Description
0	Normal operating data
1	No data (see note)
2	Undetected (see note)
3	Implausible data / outliers (see note)
4	Beam overshooting
5	Beam blocking
6	Ground clutter
7	Sea clutter
8	Beam attenuation
9	Wet radome attenuation
10	Wind turbines
11	Insects / birds
12	Ships / aircrafts
13-191	Reserved
192-254	Reserved for local use
255	Missing

Note: 'Undetected' means that the received radar signal is at or below noise level,
‘No data’ describes that a data point is out of range or in a blanked sector, ‘Implausible data / outliers’ refers to values that are not physically plausible

Comments

No response

Requestor(s)

Sebastien Villaume (ECMWF)
Robert Osinski (ECMWF)
Ana Prieto Nemesio (ECMWF)
Florian Pinault (ECMWF)
Pedro Maciel (ECMWF)

Stakeholder(s)

ECMWF

Publication(s)

Manual on Codes (WMO-No. 306), Volume I.2, GRIB code table 4.2.0.15 (update)
Manual on Codes (WMO-No. 306), Volume I.2, GRIB code table 4.106 (create)

Expected impact of change

None

Collaborators

No response

References

Holleman I., Michelson D., Galli G., Germann U., and Peura M., 2006: Quality information for radars and radar data. OPERA II deliverable OPERA_2005_19

Validation

No response

[amilan17]

@sebvi is this part of the GRIB1 migration?

[sebvi]

no this data not exist in GRIB at all.

[amilan17]

https://github.com/wmo-im/tt-tdcf/wiki/2024.11.13.tt.tdcf notes:

• Sebastien introduced the proposal
• Sibylle recommends encoding OPERA II into the title of the quality index; Sebastien suggested making it more generic instead because don't want to make a parameter for each;

[amilan17]

https://github.com/wmo-im/et-data/wiki/2024.12.03.et.data notes:
@sebvi branch is ready for your updates

[amilan17]

https://github.com/wmo-im/et-data/wiki/2025.01.14.et.data notes:
branch ready for crosschecking;