Advanced mitigating techniques to remove the effects of wind turbines and wind farms on primary surveillance radars

In the past decade many countries have launched programs to deploy wind turbines as alternative sources of electrical energy. When deployed in wind farms this technology has raised concerns from both air traffic control (ATC) and military authorities. This is due to the fact that the turbine blades return radar echoes that have the potential to distract and confuse the air traffic picture by creating false detections that can effectively mask genuine aircraft returns. Most of the mitigation solutions offered today are either primarily based on such measures as range-azimuth gating or inhibiting track initiation in the vicinity of wind farms. These draconian measures can result in a significant degradation in radar performance and potential air traffic control disruption. They may also require costly redesign of the existing radars. This paper presents a set of ´clean´ solutions that mitigate, and in some cases completely eliminate the effect of wind turbine returns. The solution is based on the combination of discrimination techniques applied at the pre-detection, detection and post detection stages of the radar signal processing chain. The suit of mitigation solutions developed does not adversely affect aircraft detection, and can be readily retrofitted to the existing ATC primary surveillance radars (PSR).