Effects of Wind Turbine Farms on Air Defence Radars

摘要

The UK Government supports the introduction of wind turbine farms as part of its alternative energy strategy but existing Ministry of Defense (MoD) Guidelines restrict planning consent for wind turbine farms within 60% of maximum instrumented range (interpreted as 74 km) and line of sight from primary surveillance radars. However, wind farm developers are increasingly questioning the validity of current Guidelines. Consequently, a Trial was conducted by the Air Command and Control Operational Evaluation Unit (Air C2 OEU) in response to a tasking from the Directorate of Counter Terrorism and United Kingdom Operations (D CT&UK Ops) to determine the effects of wind turbine farms on Air Defense (AD) radars. The aim of the Trial was to determine the effects of wind turbine farms on AD radars by considering the effects of wind turbine farms on radar performance with regard to probability of detection, tracking and displayed effects, the effects on low-level coverage due to the wind turbine farms and system set-up and observed displayed effects. It was confirmed that on the T101 radar, primary radar returns from aircraft having a low Radar Cross Section (Hawk T Mk 1a and Tucano T Mk 1) are lost when flying over wind turbines, regardless of the aircraft's height. The cause of this effect is believed to be as a result of excessive returns from the wind turbines being received in the elevation sidelobes of the radar. As a result of this Trial, the MoD has provisionally ceased automatic approval of wind turbine developments beyond 74 km but within Line of Sight from an AD radar.