Radar Interference
NATS (National Air Traffic Services) objects!
NATS En Route Pic ("NERL") is responsible for the safe and expeditious movement in the en-route phase of flight for aircraft operating in controlled airspace in the UK. To undertake this responsibility NERL has a comprehensive infrastructure of radars, communication systems and navigational aids throughout the UK, all of which could be compromised by the establishment of a windfarm.
Scottish Civil Air Traffic Objection
Control Scottish Military Air Traffic Control
Objection
Conclusions
The proposed development has been examined from a technical and
operational safeguarding aspect and conflicts with NATS (En Route) Pic's
safeguarding criteria. Accordingly, NERL
objects to the proposal.
The degradation in the radar system over Allerdale, because of the sheer number of turbines, is a great concern. The cumulative effect could compromise air safety over our region. Obviously Peel Energy did not feel that this would be a problem.
Aviation safety is a concern, wind turbines interfere with the radar used in air-traffic control.
In Britain such worries have caused the shelving or refusal of more than 40 proposed wind farms.
The standard radar used by air-traffic control centres find it difficult to tell between a moving aircraft and the whirling blades of a wind turbine.
Radar works by sweeping a pulsed radio signal around a wide area and then measuring the time it takes for the signal to be reflected back by any objects in its path. This allows the position of those objects to be plotted on a screen.
Aircraft can normally be distinguished from stationary objects because the Doppler effect changes the frequency of the returned signal.
Although a wind turbine does not change position, its blades are moving
and these also cause a Doppler effect. The returning signal from a wind
turbine thus creates illuminated blobs on a radar screen that look just
like moving aircraft. The blobs do not keep still either! Every few
seconds , as the radar beam sweeps past, the signal is bounced back by
different parts of the turbine’s blades in unpredictable ways. The
confusion this causes on the screen is made worse when the signal is
bounced around between different turbines in the same farm.
The result is that wind farms can be impossible to filter out because the resolution of a typical long-range radar is not high enough to detect the difference between the Doppler effect caused by an aircraft and that caused by a wind turbine.
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