In addition to other technologies, the generation of electricity from wind energy offers a possible solution approach to ecological and sustainable energy production all over the world. However, wind turbines can present major problems for systems which use radio waves. Due to their size and their dynamic behaviour of rotating blades, the impact of wind turbines on electromagnetic waves is very complex and difficult to simulate or predict. The influence of wind turbines can affect the reduced detectability of aircraft in the air or on weather radar coverage and its meteorological forecasts.

Specialists from all over Europe met at this year’s EMWT Conference to discuss the impact of wind energy turbines on radio systems. armasuisse S+T also took part and was able to present its latest findings in this field.

Simulation of targets

Among other things, the experts in the specialist area Sensory Analysis from armasuisse S+T were able to present their results from simulations with the «Radar Target Simulator (RTS)». Using the RTS, objects can be emulated – in this specific case, wind turbines are simulated with electronically generated signals and transmitted to a radar sensor using the RTS. The size, distance to sensors and the speed of the rotor blades can be adjusted as desired, so that the RTS can be used to simulate signals in very many different ways. The RTS was tested in measurements on wind power plants in Le Charrat, in order to find out whether it could simulate the signals of a real wind turbine. It was revealed that the RTS could reproduce and replicate the signals of the wind power plant.

However, it was not just the simulation of targets that was examined in Le Charrat. Drone detection tests were also performed in order to examine the impact of wind power plants on their detectability. A drone flew close to the wind turbine for this purpose. The conditions under which flying objects can disappear from radar screens when flying close to wind power plants was demonstrated.

The interaction with the specialist departments at the conference enabled a common understanding of the issue to be reached and results to be compared with each other. The work was carried out as part of armasuisse’s research activities in the Reconnaissance and Surveillance programme and the findings will be taken into consideration by the GS DDPS and the Swiss Air Force when assessing applications for new wind turbines.