About the stations
From sensor to screen — how weather observations are produced and transmitted
The global observing network
Organised primarily through the RADOME and ÉTENDU networks, Météo-France observations cover mainland France and the overseas territories. They also contribute to the international exchanges needed to monitor an atmosphere that has no borders.
Météo-France maintains automatic stations in the overseas territories, including the Caribbean, French Guiana, Réunion, French Polynesia and New Caledonia. These sites form part of a network of around 1,150 automatic surface stations across the French territories.
These stations contribute to the WMO’s Global Observing System (GOS). Their role is to provide consistent and standardised data, including BUFR-formatted observations, for use by numerical models and meteorological services.
To analyse the atmosphere and produce forecasts, meteorologists need accurate, recent observations. That is the role of Météo-France’s automatic weather stations (AWS).
1. Station manufacturing and integration
Unlike a smartphone or a car, a weather station doesn’t have a single consumer-facing “brand”. Météo-France relies on highly specialized companies to design and integrate these instruments.
| Item | Key details |
|---|---|
| Manufacturer | One of Météo-France’s major suppliers is the French company STERELA. |
| Technical name | STERELA offers ranges such as Mercury stations, adapted to different use cases (synoptic stations for general forecasting, road weather, agrometeorology). |
| What they provide | These companies don’t just install sensors: they deliver a complete system (sensors, an acquisition unit, and communications). |
2. Météo-France networks: RADOME and ÉTENDU
The names RADOME and ÉTENDU refer to the networks used to organize these stations and ensure efficient coverage.
| Network | Meaning | Why it matters |
|---|---|---|
| RADOME | Extended Meteorological Data and Observation Acquisition Network (historical name of the main network). | The core stations providing baseline variables (temperature, wind, pressure, humidity) at high frequency (as often as every 6 minutes for some). It forms the backbone of Météo-France surface observations. |
| ÉTENDU | A broader term referring to the full set of Météo-France automatic surface stations. | It includes RADOME, as well as partner stations or stations dedicated to specific uses (road weather, mountain sites, etc.). |
3. What the station measures
A station is a set of high-precision instruments that measure key atmospheric variables. Accuracy is critical, which requires specialized sensors.
| Variable | Sensor type and explanation |
|---|---|
| Temperature | Typically a platinum resistance probe (Pt100) placed in a ventilated shelter (to avoid solar heating) at 2 meters above ground, following WMO standards. |
| Wind | Increasing use of ultrasonic anemometers (no moving parts). More accurate and robust than cup anemometers, mounted on 10-meter masts in open exposure. |
| Humidity | High-precision sensors (capacitive polymer) to measure relative humidity and compute the dew point (useful for fog/dew). |
| Precipitation | Tipping-bucket rain gauges measuring volume with fine resolution (e.g., 0.2 mm per tip), to track totals and real-time intensity. |
| Pressure | Very stable pressure sensors for atmospheric pressure—fundamental for tracking highs and lows (anticyclones and depressions). |
4. From sensor to application
Acquisition: each sensor sends electrical signals to the acquisition unit (the station enclosure).
Processing: the unit converts these signals into physical values (using calibration curves) and stores them.
Transmission: every 6 minutes (RADOME network), the unit sends data via GPRS, 4G, or satellite to Météo-France’s collection systems in Toulouse.
Distribution: after validation, the data feeds models and meteorological services, then becomes available to the public, including through LiveStation.