The development of windfarms – groups of wind turbines – around the world to address the need for renewable energy sources has to be done in cooperation with civil aviation authorities when required. Wind turbine blades’ radar reflections can either appear as false aircraft detections on radar displays or mask the real aircraft tracks, increasing the probability of real targets being lost. The slightest uncertainty regarding an aircraft position in the sky, even for just a few seconds, can have significant consequences on air traffic safety and security in countries with a growing wind industry can be significant.
Addressing this issue, however, is a challenge in itself. It requires careful adjustments to the radar’s signal processing capabilities so that sensitivity is not too high – creating too many false alerts – or too low – decreasing false alerts to the detriment of real targets.
Windfarm mitigation in civil air surveillance
Leveraging years of experience in the development of radars for various threats, missions and purposes – whether civil or military – Thales offers the STAR NG (S-band up to 100nm) and the TRAC NG (L-band up to 250nm) radars, both including a feature enabling a proper a windfarm mitigation.
The Windfarm Filter is a dedicated algorithm that uses a specific adaptive Constant False Alarm Rate (CFAR) mechanism designed to minimize track loss and reduce false alarms above and around windfarms. It can be integrated to address both civil and military needs and, as a software capability, can also be activated into other Thales ATC radars already in service.
Finding the most appropriate solution, and the most accurate balance for the algorithm, is specific to every client’s needs. What works for one radar, operating around one windfarm characterised by a certain type of wind turbines, may not work for another radar in a different context. Evaluating the impact of each windfarm on potential radars is therefore crucial to de-risking investments.
To this end, Thales has developed a unique simulation tool, WINRAD, for evaluating the impact of proposed windfarms on its radars. Combining environment characteristics – terrain and windfarm visibility, windfarm boundary and layout, wind turbines – with radar behaviour, WINRAD can confirm the windfarm’s impact on radar performances. On this basis, it can then predict achievable performance criteria over and around the windfarm area, supporting the identification of the most appropriate radar solution to maintain required detection performance while reducing the false alarm rate.
Windfarm mitigation in military air surveillance
Thales’ military air surveillance are all 3D radars using AESA technologies and sophisticated doppler analysis. This enables the radars to separate the target signal from wind turbine signal and discriminate between wind turbines and targets. As a result no plots and tracks are reported on wind turbines and at the same time minimize performance effects on real targets.
Working closely with all stakeholders
Thales works closely with all the stakeholders in the aviation sector, ministries of defence and the wind energy industry to provide an end-to-end service to identify and deliver the optimum solution for each circumstance. Through our windfarm tolerant radars, our radars not only continue to ensure sky safety; they also contributes to unlocking the development of windfarm, increasing their contribution towards a greener future.
Did you know?
- The Thales Wind Farm Filter is field proven, with several dedicated flight trials performed in difficult circumstances, such as low Radar Cross Section (RCS) targets, ground and sea clutter, and low altitudes.
- The Wind Farm Filter is already operational in Europe and Africa