New BUFR descriptors to represent IRS data quality information for MTG

[marijanacrepulja]

Introduction

• Mission : MTG
• Data type : IRS-L1B
• Incoming format : hdf/netCDF
• Goal : This is to support assimilation of the IRS data in NWP models.

Proposal: for the new BUFR descriptors to represent IRS quality information. In the scope of MTG mission, we need to request new flag and code table to represent this new product format specification flag

Amendment details

1. Add a new element in table B for IRS quality flags

F X Y	ELEMENT NAME	UNIT	SCALE	REFERENCE VALUE	DATA WITH (bits)
0-33-120	IRS SPATIAL QUALITY	Flag table	0	0	14
0-33-121	IRS DETECTOR QUALITY	Flag table	0	0	5

2. Add a new CODE/FLAG TABLE 0-33-120for IRS spatial quality

Bit No	IRS spatial quality
1 - 4	Reserved
5	Solar straylight correction warning
6	Solar straylight warning
7	Noisy detector sample warning
8	Undersaturated detector sample warning
9	Saturated detector sample warning
10	Dust
11	Cloudy
12	Limb view
13	Space view
All 14	Missing

source

---

3. Add a new CODE/FLAG TABLE 0-33-121for IRS detector quality

Bit No	IRS detector quality
1	excluded detector sample
2	noisy detector sample
3	undersaturated detector sample
4	saturated detector sample
All 5	Missing

------------------- ANNEX --------------------

Requestor(s)

• EUMETSAT
• ECMWF

Stakeholder(s)

ECMWF
Met Office

Expected impact of change

MEDIUM

Consultations

No response

Data exchange plans

No response

Comments

No response

[amilan17]

https://github.com/wmo-im/et-data/wiki/2025.10.07.et.data notes:
Antoine presented the proposal and he is double-checking the flag table details

[amilan17]

https://github.com/wmo-im/et-data/wiki/2025.11.04.et.data notes:
Antoine said it's still in progress. If they don't provide something by December meeting it will be pushed to FT2026-2

[antoinemerle]

@amilan17 @marijanacrepulja,

I did not receive any confirmation that it will change.

I am already created the new data and will push the changes by end of the week.

[amilan17]

https://github.com/wmo-im/et-data/wiki/2025.11.04.et.data notes:
@antoinemerle will create sample data, update branch and open PR

[antoinemerle]

HI,

commit pushed : 7b11e96
sample data is here :

irs_quality_wmo_ver_45_46_47.zip

• with wmo version 46
• with wmo version 47
• with wmo version 45

local table are as expected

            {"code": "033120", "name": "irsSpatialQuality", "units": "Flag table",
             "scale": 0, "reference": 0, "width": 14},
            {"code": "033121", "name": "irsDetectorQuality", "units": "Flag table",
             "scale": 0, "reference": 0, "width": 5},

or in eccodes world

033120|irsSpatialQuality|table|irsSpatialQuality|Flag table|0|0|14
033121|irsDetectorQuality|table|irsDetectorQuality|Flag table|0|0|5

[amilan17]

https://github.com/wmo-im/et-data/wiki/2026.01.13.et.data notes:
@marijanacrepulja will validate
@antoinemerle will update amendment details with the updated FXY numbers