Aircraft flying over wind farms are indistinguishable to primary surveillance radar from the clutter caused by the wind farm’s turbines.
Why should this be of concern to airports? Because the number of wind farms across the globe is growing, and as they become more commonplace, there will be operational and financial implications for
the world’s gateways.
Up to this point, airports and air navigation service providers have been able to stall wind farm development by lodging complaints with the relevant planning authorities.
However, two converging issues mean this impasse simply cannot continue. Global air traffic is on the rise – EUROCONTROL predicts that air traffic levels in Europe alone will almost double by 2030 – and the global search for new energy sources means that governments around the world are committed to reaching tough renewable energy targets.
In the UK, for example, the Department of Energy and Climate Change forecasts onshore wind farm deployment will increase by 250% by 2020.
To ensure that airports can continue to operate a safe and financially viable air service, a solution must be found.
Mitigation or a solution?
There are several technologies at various stages of development that claim to have the answer but the majority of these use variations on the very same primary service radar whose problem they are trying to fix.
None of them actually have the ability to differentiate between wind turbines and aircraft. Consequently all these approaches have limitations, some severe enough to render them impractical.
Crucially, airports should identify a solution that allows them to operate confidently at a separation of three nautical miles.
One potential solution is a newly invented three-dimensional holographic radar that overcomes the limitations of current mitigation technologies.
Indeed, instead of increasing the resolution of existing radar or removing areas of concern, the 3D Holographic Radar™ – manufactured by Aveillant – can actually differentiate between the returns produced by wind turbines and those of aircraft.
The radar data processor is able to intelligently filter out wind turbine signals, leaving just aircraft returns to be passed to the airport ATM system.
Whereas conventional radar rotates and sweeps a focused beam 360° around the horizon, such technology employs a stationary planar array.
Its transmitter illuminates the whole field of view all the time, while forming receiving beams in all directions.
To the non-expert, the best way to explain the difference between traditional radar and new technology, is to think of the former as like sitting in a darkened room whilst swivelling around in an office chair holding a torch.
In the case of conventional radar, the beam only sees a target for an instance once per rotation making it hard to tell which is an aircraft and which is a turbine.
However, with the new technology you uncap the torch bulb and allow it to light up the whole room – seeing the same 360°, but in three dimensions, all the time making it easy to tell the difference.
The result is like the difference between a cartoon flip book and 3D cinema.
The fact that more and more airport operators are seeking advice from technology providers as to the best way of dealing with this issue, proves that the industry is aware of the potential threat wind farms pose to their long-term success.
In my opinion, the most important thing for airports is to do right now is to educate themselves on the different solutions available so that they can find the best technology for their aerodrome.
Airport managers need to engage with air traffic controllers and raise the bar high when considering solutions. Technology providers should be asked to prove their claims and airports should make sure they are ‘future proofed’ for how this dynamic situation may look in the decades to come.
This is a crucial issue that not only affects the world’s ability to produce renewable energy, but also airports’ ability to control traffic safely and profitably.
About the author
David Crisp is CEO of UK-based technology company Aveillant.