Officials from BAE Systems Insyte will be at the show this week to brief potential customers on a solution to a rapidly-emerging problem affecting air traffic control radars.

BAE Systems Insyte

The drive - particularly in Europe - to cut down on 'greenhouse gas' emissions under the Kyoto protocols has seen an explosion in the number of windfarms on the continent.

However, the sheer bulk of the windfarm towers, together with the Doppler effect of their rotating blades, is increasingly throwing up unwanted radar returns. These mean that, in the UK, for example, with its congested airspace, more than 50% of planned windfarms are attracting objections on the grounds of radar reflections.


In an attempt to mitigate the problem, BAE Systems Insyte is partnering the UK Ministry of Defence to demonstrate a software filter on an RAF mobile Tactical Watchman radar that removes unwanted windfarm reflections from an operator's screen. Funding is being provided by the Department of Trade and Industry and the British Wind Energy Association, a trade body.

An initial period of tests earlier this year saw the Tactical Watchman being positioned on a hill in mid-Wales from which several windfarms are visible, to gain baseline readings.

Specialised algorithms designed to eliminate most of the windfarm echoes have been installed on an Advanced Digital Tracker (ADT), a post-processor that can be added to an existing radar. Next month, a new series of tests will be run from the same site to test the approach.

"A radar signal contains a lot of information that's not generally used in a conventional radar display," explains Ian Metcalf, head of business development for customer support at BAE Systems Insyte.

"The algorithms use fuzzy logic that takes each element of that hidden data and asks 'Is that, on a probability basis, more likely to be a plane or a wind farm?' and uses information captured over a period of several radar revolutions to build up a gradually increasing probability."


The technology is derived from military electronics used to filter out unwanted radar returns in critical defence situations - for example, the track of a missile threatening a warship from the false tracks generated by waves or even seabirds.

If trials over the latter half of this year prove successful, Metcalf hopes that agreement will be reached with the various interested parties to agree that the ADT represents a robust solution and that certain categories of windfarms will no longer attract objections from air traffic control.

Insyte also believes that it will be able to advise developers on the alignment and size of individual wind turbines within windfarms to minimise radar reflection problems.

Source: Flight Daily News