An article in today’s newspaper refers to the act that there were objections to the building of new wind subsidy farms in certain areas because the rotating blades obscured military radars and interfered with the ability to detect incoming airborne threats.
I would have thought that it would not be beyond our current abilities to program the radar installations to ignore the windmills they can see? Granted, the turbine blades will not be turning at the same speed all the time, but the arcs they sweep will be constant? Surely it would not be that difficult to program the radars to distinguish between an object barrelling in at the speed of pffft and a known obstruction?
I await enlightenment.
Boadicea's Chariot 
Sorry darling, I don’t know the answer to your question, but what I do know is, I hate wind turbines, and would gladly bomb the lot, they are neither use nor ornament Bravo, orrible, eyesores.
Hello Bravo: I’ll have a go.
Radar is a bit like looking for things in the dark with a narrow beam flashlight, one can only see what is directly in the beam of the flashlight, and those things only as a result of their reflection of the beam. If something reflects the beam other things directly behind the object cannot be seen or are much more difficult to see because the stuff in front has reflected all or most of the energy. Ignoring or programming out what is first in the beam will not make the hidden things visible, the stuff in front has robbed the beam of much of its energy so there is little left to be reflected by the stuff behind.
Now for the damn windmills, most are arrayed in groups on hilltops effectively making the hill higher, the beam cannot be curved over the hill or around the obstruction so they form a shield preventing the detection of threats. A solution is a second radar looking from a different direction and not in the direction of the windmill/hill. Expensive.
I’m sure I have missed some or all of the point here in light of (pun) modern technology but I have been out of the radar business for forty years.
Bearsy can probably add a lot more.
I’d be interested to know where the perceived threat was from, Bravo doesn’t give us a link, Scotland perhaps?
I suspect the Doppler effect is in evidence here, But I also suspect it is more to do with the total paucity of any evidence that wind power is, in any way, cost effective or environmentally friendly!
I would also think that modern missiles with ‘ground hugging radar’ are given an advantage by the interference caused by these windmills, If the windmills are ‘reflecting signals’ it’s possibel that they could be having the same effect as ‘chaff’, which would make in incoming missile difficult to detect amongst all the spurious signal returns.
I haven’t a clue, Bravo, but the more objections the better, as far as I am concerned.
I hate the things.
Sorry, this was the story: http://www.telegraph.co.uk/earth/energy/windpower/8726922/Military-radar-deal-paves-way-for-more-wind-farms-across-Britain.html#dsq-content
Hmm!
Thanks LW & FEEG. My involvement with radar at the pointy end of beam-shaping and signal processing ceased around ten years ago, and although at that time I was involved in the program which saw the TPS-77 procured in Australia against strong competition from UK and Italian radars, I have little to add – and none that might make sense to Charioteers who are not familiar with 3D primary radar.
However, to address Bravo’s main point –
the simple answer is “Yes, it would be that difficult.”
I know of no magic processing possessed by the TPS-77 which isn’t equally available in its competitors’ products. I suspect that the LM sales engineers have done a snow job on MoD PE (or whatever they’re called these days).
For a long general discussion for non-technical readers, I found this paper – 10 years out of date – which will probably bore the pants off you. It was considerably out of date in many areas even back then, but it does give some idea of the scope of the problem.
If you’re really interested this PDF file may be of interest.
FEASIBILITY OF MITIGATING THE EFFECTS OF WINDFARMS ON PRIMARY RADAR
It turns out that this is occupying a lot of minds. A search for ‘wind turbine radar interference’ produces some up to date information, beyond that which bearsy and I posted.
Easy answer to the Radar problems of those monstrosities – remove them. We looked at a British programme the other night which showed rows and rows of the wretched things in the sea – what an eye-sore!
Snap. PB.
Fascinating, Bearsy. Non-techie so clicked your link. Noticed straight away that it was an Embran source so wandered off in that direction first. Googled Spaven Consulting and discovered that they appear, in sum, to be Malcolm Spaven, MA (Honours) Uni of Embra (obviously acceptable) and MSc Rural and Regional
Resources Planning from the University of Aberdeen.(no comment).
In various submissions, he seemed to me to be claiming that his expertise lay in the impact of environmental noise in relation to the creation or expansion of airports. Then he appears to have discovered wind turbine development as a potential source of income for an expert witness. I could, of course, be doing him a disservice.
I have only skimmed your link and Mr Spaven’s other contributions to the sum of human knowledge but I have this nagging feeling that he might fall into that category of expert who tells whoever is paying him exactly what they want to hear.
I could, of course, be wrong.
Interesting JM. The technical content could have been written by anybody will a little experience in the field. I have a suspicion that it was put together from books and a few chats with operations staff. So I’ll go along with you – it’s certainly what most consultants do. 🙂
So why “no comment” about the Resources Planning from the University of Aberdeen, JM? We have after all nearly one hundred years more experience than the University of Edinburgh. Makes me feel your last sentence could be correct.
Och and ochone Sheona.
You;ll surely forgive me for a wee bit dig at Aiberdeen and all thereanent. As you well know, it’s what we Jocks do internecinely.
Many of my best friends come from Aberdeen (usually in the same taxi to save money).
Just seen this. As the pig said to the chicken, when asked about his contribution to the breakfast menu: “I’m happy to see you getting involved, but remember, I’m committed.”
The mastodonturbines are set to arrive here very soon. Little comfort in the fact that the Danish gubmint have slashed all wind-power development spending next year by 90%. The landscape and the rural peace around here are to be ruined for ever.
The tall masts and taller blades interfere with our air defence radar.
We cannot possibly deny that wind turbines are a good thing (sarcasm).
So…
Put the radar receivers on even taller towers or higher ground.
OK it will cost a fortune and destroy thousands of acres of unspoilt mountain terrain but at least after 50 years we will have neutralised our carbon footprint. Shame that the entire network of turbines will need renewing every 15yrs, but we simply cannot scrimp when it comes to lining the pockets of the wind turbine builders.
LW has it spot on layman wise. Imagine you take a digital photo, upload it to your PC and notice that Cherie Blair has managed to get her gurning fizgog in the backfield. Naturally you boot up photoshop and set about the business of airbrushing the painfully grim visage out of the snap. Its easy to cut her out of the image, but the detail that was behind her is not available so the best you can do is make it up. Replace the monstrous Cherie with a slightly more charming wind turbine and theres your response.
Seemples. 🙂
Bearsy and Ferret: Sorry to badger this post (poor old stripey, whatever happened to him?). I did read the several .pdf’s and the recommendations thereon. Are phased arrays used in ATC or are they still mostly military? Would a phased array system help some with this problem? The ability to “hover” the beam on a questionable return should provide some ability to resolve the issue. I have no real knowledge of phased array systems except the basic concepts, but I did some work with Westinghouse on packaging the early solid state array elements back in the eighties.
I’m following the discussion, btw, thanks all.
JM, I forgive you your comments or lack of them on the ancient Universities, as they were when Edinburgh was founded, of Aberdeen. I trust you will forgive me sniggering every time I read another article on the Edinburgh tram debacle.
Please remember that I am between 5 and 10 years out of date in this field, so my answers should not be treated as gospel, or quoted without reference to a current expert, but I don’t believe there are any fundamental mistakes in what follows –
First of all, ATC (Civilian Air Traffic Control, or ATM, Air Traffic Management).
This is not quite sufficient for small GA (General Aviation) operators, but then they receive a different standard of guidance and they obey other, very specific rules.
SSR will be almost completely unaffected by wind turbines. I won’t bother to explain why, but you can take this as firm. Satellite ADS is completely unaffected, of course.
The ATM Services’ function of States does not include intruder alert
Civilian primary radars are 2D since the cost of 3D is exorbitant and cannot be justified for what is merely a backup function.
So forget the civilian environment totally.
Military applications
LW – 3D radars (including both phased array and others [solid state, like the original Plessey AR-3D]) do have the ability to do beam-to-beam discrimination and to be commanded to ‘dwell’. They all include both pre-detection and post-detection mechanisms for eliminating clutter and ECM. The TPS-77 is, of course a phased array radar, but there are several other excellent models manufactured by all the usual suspects – and all have at least one mobile version.
I would need to see the Operational Requirement before commenting further, but I do not believe that anything like the full story has been released about this purchase. It’s probably classified, anyway.
😀
Thanks Bearsy: I was first tempted to suggest that the operators be obliged to fit a a secondary radar transponder to each windmill but that would surely make a mess of what came back.