It's done acoustically
And it isn't a secret. It is described in patents:
WIPO Patent Application WO/2008/075092
WIPO Patent Application WO/2008/075092
British boffins have devloped a cunning new method of transmitting high bandwidth data - plus power - through tough solid barriers such as submarine hulls or tank armour. The tech is being touted as a way of adding modifications to subs or armoured vehicles cheaply, but it seems that there are also other, highly secret, …
If it can go through a sheet of metal, it's not electromagnetic, unless it uses an unreasonable amount of power. That leaves vibrations. I would imagine the power is transmitted via some sort of acoustic resonance couple to a piezoelectric crystal. Given that I came up with that in a few minutes, how then can a patent be granted for something like this, since it fails the 'non-obvious' test (at least in my eyes). Admittedly, the engineering involved may be a technical feat, but still...
Then we wouldn't have been able to patent it.
The patent drawings seem to rule out any of Lewis's 'blue sky thinking'. It's pretty much point-to-point transmission. However, this particular patent also doesn't cover transmission of power. If the power is generated from harvesting those accoustic signals, it's going to be a) inefficient and b) very low power.
Given a known transmission medium it would be easy enough to build a speaker system specifically tuned to be highly directional, essentially a phased array. The acoustic signal produced would be very beam like and concentrated within the "beam" whereas outside the "beam" the signal is highly attenuated by the phase relationship between the arrays sources.
The interesting thing is that it would work well in strictly solid mediums but it falls apart once the structure becomes soft, has air gaps or anything where the speed of sound changes dramatically as it might in a laminated structure designed to dampen sound.
Well, that's it then. I'm off to install acoustic tile, rubber wall panels, tapestry and thick carpet over the tin foil.
"But of course the Americans have got this and it's much cheaper and better. BAe is only there to take backhanders from government ministers. We shouldn't be using british taxpayers money to keep british scientists, engineers and workers, employed."
There you are. I've completed it for you.
I'm not sure that I buy this: Surely any kind of acoustic through-hull transmission is a no-no on a submarine, what with them trying to hide from sonar and all? I mean, if the sound resonates through the hull, then it will couple into the water too right?
The only way I can see that an acoustic method would work would be if they have used a frequency which is attenuated _drastically_ more by water than it is by metal/glass.
Liquid water can only support the compression wave propagation mode of ultrasound. They could be using shearwaves. Above the critical angle they will reflect at the far wall, and not mode-convert into water-borne compression waves.
If it is an acoustic method that is being used, how will it cope with composite or Chobham armour, that is layered steel and ceramic?
I hazard a guess deducing armour composition is the spooky application. The transmitter needs to sweep the frequency range to map attenuation and phase shift so the receiver can compensate accordingly. This information probably gives you more than a good idea of the composition of the materials between the pair. It might even be possible to have transmitter and receiver on the same side if that's all you were interested in.
"The world of bugging and clandestine surveillance - and countermeasures against these - may be about to suffer another technical upset in the near future."
Err ...methinks that should be worded to reveal a paradigm shift in emphasis towards future secrets exposure being the bugbear of counterintelligence and clandestine surveillance services, for such would render them obsolete with nothing of novel value to protect/trade/leverage/abuse.
"In particular the intelligence services are known to have extensive technical shops of their own, potentially well able to develop this sort of kit - perhaps some time ago, in fact.
It doesn't seem impossible that even now MI5/SS, MI6/SIS and GCHQ have equipment similar to BAE's sub/tank datalinks in the field, siphoning information undetectably out of systems or locations considered impenetrably secure by their owners. It also seems plausible, given the request from "other government parties" that BAE not reveal details of their gear, that there is some way to frustrate such methods once you know about them." ........ Such a pity that they do not have the Intelligence to use what they would then have, and know, to most exclusive and priceless global effect. Also-rans in Intelligence Stakes are always habitual total losers.
as in 18Mbits of audio around a 40MHz carrier, probably there's the medical world ceramic based phased-array transmitter systems as used in ultrasound scanners and the receiver could be based on that family of piezoeletric plastic PVDF polymer mixtures that was popular in the 1980's. see IEEE website "Review of transducer applications of polyvinylidene fluoride" and later articles ieeexplore.ieee.org/iel5/2214/4642706/04642711.pdf. (even mentions a POSFET piezoelectric-oxide-semiconductor field-effect transistor amplifying device)
it should be easy to find these noisy/lossy WBAF devices in the wild, a parabolic reflector to posfet transducer to real time RF spectrum analyser, I'll order some bits from RS immediately!
I seem to remember that the point of a Faraday cage is that potential is equal at all points on the surface, so an externally varying potential (e.g. an electromagnetic wave) cannot be observed within it. Practically, Faraday cages have limitations based on the conductivity of the material they are made from and any gaps within (around doors, for instance).
But if this thingy can penetrate a Faraday cage electromagnetically (by using a particular selection of frequencies, for instance), that doesn't stop somebody from making a better Faraday cage. Preferably one that uses superconductors.
"it's possible to imagine a bug, camera or wiretap of some sort clandestinely installed inside a building, drawing its power wirelessly from equipment outside the walls and sending its harvest of data out by the same means."
Imagining it might be possible but delivering it wouldn't be. If there's enough wireless power coming in to keep the bug alive and to transmit a signal back, there's enough for bug-detectors to detect.
Unless we're talking the same kind of BS that was in that Ian Pearson press release the other day.
The Russians bugged the American Embassy in Moscow with a passive RF device, which fits the description "drawing its power wirelessly from equipment outside the walls and sending its harvest of data out by the same means".
Probably more readily detectable these days... now that we know about such things.
I shall have to look up that patent application while it's still there. Aside from sound, what else could travel through a submarine hull? One could have a glass window, and use a light beam. One could use X-rays, but they don't go that far even through air. (And communication by neutrinos is strictly science-fiction, of course. And don't get me started on moving a heavy weight around in the submarine to send gravitational waves.)
And a submarine hull isn't, and doesn't have to be, a perfect Faraday cage, But the trouble historically with radio from submarines is that the salt water around them forms a very effective barrier against anything but the very lowest-frequency electromagnetic signals.
Acoustics, if they're not at the frequency one is looking for, could certainly work. Why, one could have submarines mimic whale songs.
What makes you think X rays don't travel far through air?
X rays are electromagnetic waves, the same as radio waves. The difference being X rays are higher energy. If X rays can travel a hundred miles, I'm pretty damn sure X rays can! That is, if can produce them with the same power output.
Perhaps you're getting confused with alpha or beta radiation which are ionising radiations.
If X rays don't travel far in air, then the question is what absorbs them? Air certainly doesn't absorb them, isn't that the point of them:? It's dense matter such as bones, lead that absorbs them.
...that's what is.
DSL modems have successfully solved the problem of transmitting high data rates through crap channels with lots of impedance mismatch. This occurs when there are cheap connectors, coils etc in the channel.
If you go into the ultrasound domain, two different materials adjacent to each other can be thought of as an impedance mismatch.
All they most probably did was to hook a DSL modem to a power amplifier and that to a piezo transducer. On the other side there is just a piezo transducer which will make the ultrasound an electric signal again. The DSL modem wil handle all the signalling and bitrate distribution to the individual frequencies and the transmission characteristics of that specific frequency.
For power transmission, they probably use a more narrowband peizo crystal that accepts lots of amplitude. Ultrasound is already used in industry and medicine to project lots of power into small volumes. One application is ultrasound-powered welding (!).
The BAE guys just hooked up some of their sonar transducers to a modem.
Using passive sensors and actuators powered by ultrasound through walls has been looked at for hostile environments. Maintaining atmospheric pressure in deep space or on the Moon or against hostile environments (lunar and mars dust is *very* nasty) and worse case somewhere like a descent into the Jovian atmosphere.
The concept has also been looked at to power/interrogate sensors across a whole buildings plumbing system.
Ultrasound transducers are available into the Kw at 10s of MHz. PVDF and various ceramics can be built as phased array devices or just focused by a shaped lump of material like a light lens.
IIRC absorption is proportional to frequency so at a high enough frequency any leakage will be absorbed very close to the sub. Note modern subs seem to have some kind of sound deadening rubber matting on the outside. I *suspect* the kind of stuff they want this to power/control would be outside the pressure hull but *inside* the layer of these tiles (presumably at ambient sea pressure).
The electromagnetic approach was developed partly in Wales in the UK, using 2 circular transformers on either side of the rotating joint on the ISS solar array. The team demonstrated non contact data rates in the Mbs range and 10Kw power transmission levels. Pulsing 10kw through the steel hull of a large undersea vessel is likely to make it pretty visible to a Magnetic Anomaly Detector an an ASW aricraft
What *might* be secret is if they have found some particularly clever way to boost the conversion efficiency, which is more important if you want to power something needing some serious grunt, like the transducer array on an active sonar.
Surely reference to "UK Government" is a bit inaccurate and should be corrected to "UK Whitehall"?
Government is a different arm to UK civil servantry although one may be forgiven for thinking that they are the same.
Fact is the are not.
UK government tends to be elected whereas UK civil servantry runs the country.
"UK government tends to be elected whereas UK civil servantry runs the country." .... Anonymous Coward Posted Monday 19th July 2010 22:55 GMT
And it appears to be just a sub-prime media concoction, with them wasting valuable time and hogging precious bandwidth, acting out a perverse and subversive version of ..... the Big Brother Houses of Parliament, Commons and Lords.
Although there does appear to be a novel twist with the Eton boys having a go at playing lead with their Big Brother Society clone........ but without them knowing and sharing how money is invented and provided for free, are they beaten before they are even started, and merely servants and puppets to do as they are told to those who control the money honey and IT supply.
What do you call a bunch of arrogant pretentious tossers pimping democracy for media outlets? .... A labouring government in ignorant denial of impertinent important pertinent facts.
I see there are no zombie words flowing from a non-zombie mind - a mind that embraces humanity and human-ness in a modestly human way?
Unlike the clay form that resembles human form, moves and speaks as in human form yet simultaneously equates a lack of cherished, admires (and much to some) essential humanity?
Oh how sad is the lack, lack, lack that brings inhuman, un-human, arc-human, a-human and possibly dis-human to life, worries, works and woes. Moreover the still to joys, cherish and beauty, beauty, beauty that no longer can even aspire to give beauty back, back, back?
Ah the soul-less, soul-forgotten or merely never ever existed soul with soul no more?
"Be Careful: They could even be reading this blog entry with Their high tech equipment!" ... Ken 16 Posted Tuesday 20th July 2010 10:05 GMT
Their abiding problem though, will always be in making Perfect Sense of what they would be reading, to know of what is in the planning, and that is something a lot more difficult, and probably will remain for them, a practical impossibility which will always result in them be late to the party and reactive to events, rather than there being in their ranks any stellar leaders creating them for others to follow blindly and sublimely.
Their supposed spooky snooping systems which allegedly are able to hoover up all emails and analyse them for interesting content are always being tested for Fitness of Future Purpose with probably even the likes of the Register doing its bit for the Future for there is at least one running trial betatesting IT with a most recent Re: AI Perfect Storm Clouds message passing through the Ether, searching for Advanced IntelAIgents.
X-rays are absorbed by water vapour in the air, otherwise we'd all be fried by incoming. They can also travel a long way e.g. from Cygnus X-1
Submarines don't issue 'ping' sonar sounds, they digitize samples of the "sound of the sea" taken a random time earlier, and transmit that, the refelected pattern bit-shifted in time, it doesn't have to be a ping you see, any sound will do, so sea sounds are very non-noticeable.
The transmission through metal bit, try thinking at a molecular level.
"Submarines don't issue 'ping' sonar sounds, they digitize samples of the "sound of the sea" taken a random time earlier, and transmit that, the refelected pattern bit-shifted in time,"
Never really thought of this. Once your doing matched filtering I guess it becomes less important *what* is being matched, as long as you have a clear signal to put out in the first place.
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