Mobile Telephone Mast Signals Usable As Radar

caveman writes "In this article at ElectronicNews.com, BAE systems have joined forces with Roke Manor Research (part of Siemens) to further develop a method of using mobile telephone base station signals as a form of radar, capable of detecting periscopes, boats, and aircraft up to several kilometers offshore, as well as detecting vehicles and people moving into and out of areas within range. The company doesn't say exactly how accurate the system will be, but they have a similar system which calculates height which is accurate to ten meters. The parts necessary to build a receiver cost about $3000, which is extremely cheap as radar systems go."

mobile phone warfare

[!splut]

I knew that mobile phone service providers were pretty competative, but I didn't realize things had escalated into all out war. I envision strategic placement of towers to protect corporate mobile communication kingdoms...

"Sir, we have spotted what may be the periscope of a Verizon class submarine on radar!"

accuracy

[tiedyejeremy]

"Range and accuracy are also not being discussed, although Lloyd did tell Electronics Weekly that Roke Manor has a height-measuring system that works at similar frequencies and is accurate to about 10 meters. "

Is that 'accurate to a height of 10 meters' or 'accurate to within 10 meters of the actual height.

The english language is so vague... language of the english or, um, nevermind...

Celldar

[masterkool]

Here [roke.co.uk] is the CELLDAR teaming site for BAE Systems and Roke Maynor Research and here [baesystems.com] is the official BAE systems news about CELLDAR.

Slashdot Press-Release Propogation

[bill_mcgonigle]

Cellular stealth-killers
Telegraph (London), June 12, 2001

THE PENTAGON justifies the $2 billion price tag of each of its stealth aircraft by pointing to their ability to elude enemy radar. But a new invention by a British scientist could turn mobile phones into the perfect stealth aircraft locators--rendering the billion-dollar planes useless.

The Roke Manor scientists discovered that telephone calls sent between mobile phone masts detected the precise position of stealth aircraft with great ease.

"We use just the normal phone calls that are flying about in the ether," said Peter Lloyd, head of projects at Roke Manor Research at Romsey in Hampshire. "The front of the stealth plane can't be detected by conventional radar, but its bottom surface reflects well."

Mobile telephone calls bouncing between base stations produce a screen of radiation. When the aircraft fly through this screen they disrupt the phase pattern of the signals.

The Roke Manor system uses receivers, shaped like TV aerials, to detect distortions in the signals. A network of aerials large enough to cover a battlefield can be packed into a truck.

"It's remarkable that a stealth system that cost $60 billion to develop is beaten by 100,000 mobile phones," Lloyd said. A rough version of a similar system might have been used in Serbia to shoot down an American F-117 stealth fighter near Belgrade during the Kosovo campaign.

Re:Slashdot Press-Release Propogation

[iggymanz]

this will work wonderfully if the U.S. declares a war on Chicago and the surrounding suburbs or other area with 1,000's of mobile phone users and hundreds of cells, and deploys stealth aircraft against it. I don't think the cell tower spacing on most of planet earth makes this much of a concern.

Re:Slashdot Press-Release Propogation

[bill_mcgonigle]

Yeah, Chicago or Serbia...

re: or serbia

[Confuse Ed]

or china, who claimed something similar a few years ago. from this [exn.ca] 1999 article:

The Chinese appear to have turned things around. Their new Passive Coherent Location system allegedly tracks fluctuations in normal or civilian broadcasts, which function at a different frequency, and looks for distortions, reports Newsweek.

Re:Slashdot Press-Release Propogation

[Tchmil fan]

Exactly... wasn't this very technique supposed to be the one used by the Serbs to shoot down something-american-with-wings. Probably the only reason BAE et al have something sellable to crow about it is that the Serbs haven't got the infrastructure to commercialise it or they're working for them now.

Now.. that charged-plate armour that the DSTL came up with.. now that's clever... http://www.dstl.gov.uk/press/01-07-02.htm
(Well it impressed me)

tracking people

[macghillisheathanach]

The system appears to have a few uses. Detecting stealth planes has been mentioned, so its a cheap alternative to an air traffic/air defence system.

But according to the article, it could also be used as a people tracker. Such as the people moving through a parking lot as mentioned in the article. Track them going to the car park, track them breakin in to cars, track them going to dispose of their ill gotten gains and track them trying to escape whem the police turn up to arrest them.

Given the processing power available today on the sorts of computers a government can afford, it ought to be possible to keep track on a fair portion of people living in the urban areas of the world... at least while they are outside, and especially when they are in highly reflective objects like cars. Something some governments will no doubt relish. Something many other people will be very wary of.

This all depends on whether it could be made to track in a person in a crowd of people or a specific vehicle in traffic. Maybe it'll allow missing individuals to be tracked from the last known point to wherever they have ended up.

I wonder if enough detail can be gained from the return signals to actually identify the person. Maybe the frequencies used are too low for much more than determining the build of the person being tracked. On the other hand, anyone who has seen themselves on an ultra sound based scanner in hospital will know that considerabel detail may be seen with frequencies well below 0.9 to 1.8 Ghz.

And due to the fact the radio signal is there whether you are being tracked or not, there is no way to know if someone is watching your movements or not.

This is...

[l1gunman]

quite old technology really. The U.S. has had, for years, the capability to exploit such "emitters of opportunity" to precisely locate aircraft and even trace back projectiles to their launch point. It's a form of triangulation that involves resolving the time difference of arrival and Doppler difference of arrival of reflected signals to give both position and velocity information. The math is not too hard, but doing it in real time is real hard (at least it was back when I first learned of it).

What surprises me is that it would work with something with as intentionally small a radar cross-section as a stealth aircraft (with electronic counter measures to boot).

2.4GHZ or 900MHZ?

[Cyberop5]

Great! Maybe now I'll be able to find my cordless phone.

Not like it maters; no one calls me anyways.

are there cell phone masts in the areas needed?

[viksit]

sounds like a good idea..but considering the fact that most cell phone masts are way outside the normal areas where such monitoring activity needs to be done..is it really beneficial to justify spening millions on research?