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Airfield ground weather at the military airfields

Meteorological information plays a crucial role in aviation. Wind, clouds and visibility are particularly important criteria when planning flights as well as when operating an airfield. The following article presents various tools for measuring meteorological information.

Raphael Neuhaus, specialist area Command and Control Systems, competence sector Command and Control + Reconnaissance Systems

A picture shows a cloud and the address Cluster Meteo below

 

With the Airfield Ground Weather system (Flpl Bo Wet), measuring equipment is installed at both ends of the runway. The sensor data is forwarded for processing to the servers and visualised via clients.

Sketch of airfield runway with sensor system, server and clients
Schematic diagram of Bo Wet 20

The sensor data and reports (METAR - METeorological Aerodrome Report) supplied by the system form the basis for the safe operation of an airfield and for the airfield weather forecasts essential for planning flights (TAF - Terminal Aerodrome Forecast). Knowledge of the current weather at the airfield is an essential requirement for preparing and executing missions.

Due to the increasing joint use of the military airfields for civilian purposes and the standardised quality of flying weather data, it is essential that the measurement equipment and the data processing chain (METAR creation) comply wherever possible with the international civilian guidelines (ICAO).

METAR is a standardised report in short form which describes the meteorological observation of an individual airfield. Wind information such as direction and wind force, visibility, type and intensity of precipitation, cloud, height and density of cloud cover and air pressure are all conveyed. Visibility and ceiling are also shown as a colour code (colour state).

The new Bo Wet 20 system is currently being installed on the military airfields and will replace the existing Bo Wet 94 system. The Bo Wet 20 system will be equipped with new ground weather sensors from Vaisala and the software SMART from MeteoSchweiz. Using SMART, the flying weather observations can also be generated and dispatched automatically (Auto METAR).

METAR report with explanation on how to read it
Description of a METAR report
© MeteoSchweiz

Why is measuring equipment set up at both ends of the runway?

When the Föhn wind is blowing in Meiringen, the situation is such that the south wind (Föhn) blows at the southern end of the runway while the north valley wind blows at the northern end. A similar situation also exists in Locarno, where the north wind from the Verzasca Valley blows against the valley wind of the Magadino plain. It goes without saying that the pilot needs to know at take-off and landing from which direction the wind is blowing and how strong it is. And whether there is ground fog in the autumn is also an important factor.

SMART client with the data from the ground weather system
View of SMART software
© MeteoSchweiz