Date (Revision)

2026-03-10

Citation identifier

RMI-be / qpe

Status

On going

Point of contact

Organisation name	Individual name	Electronic mail address	Role
Royal Meteorological Institute of Belgium		info@meteo.be	Point of contact
Royal Meteorological Institute of Belgium		info@meteo.be	Owner

Maintenance and update frequency

Continual

User defined maintenance frequency

P0Y0M0DT0H5M0S

GEMET - INSPIRE themes, version 1.0

• Atmospheric conditions

Keywords

• federal government

• radar

• observation

• rainfall

Spatial scope

• National

Access constraints

Other restrictions

Other constraints

No limitations on public access

Use constraints

Other restrictions

Other constraints

Creative Commons Attribution 4.0 International (CC BY 4.0) This is a human-readable summary of (and not a substitute for) the license. You are free to: Share — copy and redistribute the material in any medium or format Adapt — remix, transform, and build upon the material for any purpose, even commercially. Under the following terms: Attribution — You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use. No additional restrictions — You may not apply legal terms or technological measures that legally restrict others from doing anything the license permits.

Classification

Unclassified

Spatial representation type

Grid

Distance

1000  m

Language

English

Topic category

• Climatology, meteorology, atmosphere

Begin date

2018-05-01T00:00:00

Unique resource identifier

EPSG:4258

Distribution format

Name	Version
HDF	5

Hierarchy level

Dataset

Other

dataset

Statement

The RADQPE product is obtained after a careful processing of the weather radar measurements and a merging with rain gauge measurements. The scientific basis can be found in Goudenhoofdt and Delobbe (2016). There is a continuous improvement process based on research and quality control.

WEATHER RADAR MEASUREMENTS

Radars emit electromagnetic pulses, typically with a length of 500m and a width of 1 degree. Part of the energy of this pulse is reflected back to the radar by precipitation. Radars performs scans at different elevations in about 5 minutes. Estimating rainfall from radar measurements is a challenge because of the many sources of error and uncertainty.

RADQPE is based on the 3D reflectivity measurements of the following radars:

- Avesnois, France, French National Meteorological Service

- Helchteren, Belgium, Flanders Environment Agency

- Jabbeke, Belgium, The Royal Meteorological Institute of Belgium

- Neuheilenbach, Germany, German National Meteorological Service

- Wideumont, Belgium, The Royal Meteorological Institute of Belgium

These radars exhibit various technology, scanning strategy and data processing. They use Doppler capabilities to remove non-meteorological echoes with zero velocity (e.g. hills). Some processing can lead to loss of information and make further processing difficult.

RAIN GAUGE MEASUREMENTS

The following automatic rain gauge networks are used by RADQPE:

- 91 weighted gauge OTT2, SPWMI, Belgium

- 42 weighted gauge OTT2, VMM, Belgium

- 19 weighted gauge OTT2, WL, Belgium

The quality control by data providers is void (WL), limited (SPW) or unknown (VMM). No extra quality control is performed before writing the data in the RMIB database.

QUALITY CONTROL OF THE RADAR MEASUREMENTS

- Identification of permanently contaminated measurements (hills, wind farms, interference).

- Correction for radar beam blockage by terrain

- Identification of clutter (i.e. non-meteorological echoes or signals) based on satellite cloudiness products

- Identification of clutter based on vertical profiles of radar reflectivity

- Identification of clutter based on image texture

- Identification of clutter based on dual-polarisation technology (only Helchteren and Jabekke)

FROM RADAR MEASUREMENTS TO GROUND RAINFALL RATE ESTIMATION

1. Identification of convective precipitation

2. Extrapolation to ground of non convective precipitation using an averaged vertical profile of reflectivity

3. Interpolation of missing data (vertically then horizontally)

4. Conversion of reflectivity into rain rates based on precipitation type (hail, convective, stratiform)

SINGLE RADAR ACCUMULATION AND BIAS CORRECTION

1. The movement of precipitation between 5-min snapshots is obtained using optical flow methods. It is used to accumulate rain rates over the past 1 hour and 24 hours.

2. The accumulations are adjusted by a mean field bias (MFB), which is computed based on the rain gauges measurements corresponding to the same duration

3. To remove radar calibration difference before compositing, the single radar rain rates are adjusted by the median of the 24h biases (computed at the previous step) for the past month.

COMPOSITING, ACCUMULATION AND RADAR-GAUGE MERGING

1. For the months with dominant convective precipitation (May, June, July, August), the single radar rain rates are combined into a composite by taking the maximum value of the 3 closest radars.

2. For other months, the composite is based on all values weighted based on the distance to the radar.

3. Rainfall accumulation of the composite rain rates are made for the past 5 minutes, 10 minutes, 1 hour and 24 hours.

4. The 1h and 24h composite accumulations are adjusted by the MFB correction

5. The 1h bias correction of the previous step is applied to the composite rain rate. The correction is also applied to the 5 and 10-min composite accumulations

Metadata

File identifier

RMI_DATASET_QPE XML

Metadata language

English

Hierarchy level

Dataset

Date stamp

2026-03-10

Metadata author

Organisation name	Individual name	Electronic mail address	Role
Royal Meteorological Institute of Belgium		info@meteo.be	Point of contact

Other language

Language	Character encoding
French	UTF8
Dutch; Flemish	UTF8
German	UTF8