Trials of a gap-filling air surveillance radar indicate new progress in enabling wind farms and civil airports to coexist. Further work is planned after promising initial results.
Aviation radars are typically designed to show moving objects and filter out anything stationary, but the spinning blades of wind turbines can appear as ‘clutter’ and disguise the presence of legitimate objects of interest. This often delays or prevents wind farm developments that might interfere with air traffic control.
UK air navigation services provider NATS, and the radar manufacturer, Danish aerospace business Terma, trialled the use of the Scanter system to assess its performance as an extended range wind turbine mitigation system between January and March this year.
Early results indicated that the system was not only capable of mitigating the effects of wind turbines, but could also detect aircraft through wind farm locations, even at ranges beyond 40 nautical miles (nmi).
Following this successful initial trial, the radar was evaluated during August by the UK Civil Aviation Authority as part of its spectrum release programme. According to NATS, the results confirmed that the system can detect even small targets beyond 40nmi and with good low level coverage. Based on these initial positive results, further testing is expected to be undertaken with the CAA.
As part of government plans to release a proportion of public-sector spectrum for commercial use, the CAA is analysing ways in which aviation might be able to reduce its reliance on the 2.7-2.9GHz band currently used for civil and military primary surveillance radars, including through the use of emerging technologies.
Terma developed the Scanter 4002 transceiver for detection and separation of small air targets and large surface targets such as wind turbines. To achieve simultaneous good performance for air and surface detection, it is designed as a two-dimensional coherent X-band radar with pulse compression and advanced MTI (moving target indication) processing, which provides enhanced detection and tracking of small air targets such as general aviation aircraft and helicopters between turbines.
Iain Harris, NATS director of engineering, services, said: “We’re committed to working with a range of developers and radar manufactures to find the best way for airports to mitigate the impact of wind turbines. These latest trials with Terma represent a breakthrough for airport operations, adding to our progress we have already made in the en-route environment.
“By supporting a range of technologies, we can help airports to manage their long term risk while ensuring they have a solution that best fits their individual needs.”
Michael Agergaard Riis at Terma added: “Our solutions are based on well-proven products designed for mission-critical applications which enable us to minimise risk and respond quickly to customers’ needs. The recent trials together with NATS have further strengthened our belief that the Scanter 4002 radar is a very capable solution for single radar wind farm mitigation.”