Secret?
This wasn't ever a secret was it? The day you posted the original article someone picked up their copy of E&T and said it was ultrasound!
Cool stuff though....
A mysterious secret technology, apparently in use by the British intelligence services in an undisclosed role, has been reinvented by a graduate student in America. Full details of the working principles are now available. BAE Systems' wireless through-hull comms demo at Farnborough 2010. Works through glass, too. Tristan …
Acoustic comms have been about for years. This is just the transmission of sound through a dense medium. Same as Sonar and acoustic modems, just through metal and at higher frequencies (lowering range and increasing bandwidth).
The principle behind this 'invention' is actually a well-known and well-documented pain in the ass for people doing underwater positioning; we have to make sure that acoustic positioning beacons are kept a decent distance away from, say, big steel structures we're putting onto the seabed. If not, the sound travels through the steel as well as through the water and gives screwed up results (the speed of sound through steel is much faster than it's speed in water, so you get 2 identical returns at different times).
So if he tried to patent it there are at least a dozen companies out there ready to strike down that patent. Not to mention various governments getting pissed off with him and stopping the patent being granted.
@"but what is the detection range of sonar"
Ask a Whale. They can hear sounds from over a 1000 miles away, but with all the noise in the oceans these days, that range is usually down to a few hundred miles.
@"More worrying is what 50W of ultrasound does to a solid structure over days/years"
More worrying is what it does to Whales and other marine life!
What carries for distances underwater is, I believe, the LOW end of the sonic 'spectrum" -- the bass notes of the whales' song. High-frequency sound, as with high-frequency light, is more easily scattered and dissipated in both air and water. The U.S. submarine service, for instance, uses Extremely Low Frequency (ELF) radio transmitters to send signals to vessels that remain on-station and submerged for weeks at a time.
The article here refers to "ultrasonic vibrations", so we're talking high-frequency, short-penetration waves (which probably explains the statement that "(i)t seems certain that performance could be traded for range," that is; that the frequency could be lowered, allowing greater penetration while lowering the amount of data that could be carried by those fewer cycles per second.
So, I suspect that, unless the whales are snuggling up to the sides of a nuclear "boomer", they're reasonably safe.
I was thinking the same thing. Long-distance sub-sea communication is probably INFRAsonic in nature rather than ULTRAsonic. Besides, large animals such as whales are more naturally capable of producing infrasound. On land, elephants use the technique as well, IIRC, sending infrasound along the ground.
Sound doesn't travel very far at high frequencies, too much is lost. Underwater at the upper range of human hearing nothing over a couple of kilometers would be detectable no matter how "loud" it was. Half the energy would be lost in the first km at 20,000Hz and then half again in the next km.
At the lower end of human hearing 20Hz it would travel hundreds of km for a whale song level of volume.
Whales use low frequencies which travel far. Ultrasound does not travel far and will be reflected or absorbed within a short distance.
The 50W is not getting radiated out into the ocean if it is being harvested for use by a device. There will be leakage none the less. Likely that amount of ultrasound within a room would be quite obvious to some sensors.
You all suggest that this kind of tech is exclusively gonna be used in marine-vessels.
You still need that outside power-source to drive those 50W. If it's going to be used it'll be on the inside of submarines etc. to stop cutting holes i/t various compartments for data- and power-cables.
In space however... there are no whales :-)
You could interlink various space-crafts'electrical and data signals just by physical contact with these transducers. It would make coupling the various space-modules on the e.g. ISS much easier (and quicker).
Anyway all these type of "inventions" still need some electrical source. The main global problem today is how we're gonna make that source (without dependency on fossilized resources)? Ppl should concentrate more on searching for a viable long-term energy-solution instead of these electric-or electronic gimmicks.
And then we should prioritize space travel and off-world colonization as this planet is becoming filled up with human trash.
Just MHO.
Sonar is a strange thing.
If you're in a submarine and you send out a sonar pulse everything else in the water knows where you are.
a large proportion of Sonar arrays are passive (no sound produced) rather than active, they listen for other noises, while they have their limitations (you get echo's and left and right get confused, distance is also not as good) they would probably pick up pretty much anything that makes _any_ noise.
active sonar is no good for war/stealth situations, and is not the cause of whales going ditzy, that is down to the trials of infrasound for communication (travels faster in water than in radio in air, much faster messaging) and I believe that the trials by both US/UK have had to change to compensate for the known whale related issues.
The latest passive acoustic (and sometimes-passive acoustic) sensors (in use with both the military and commercial sectors) are great- they can be used to, say, detect intruders- and these can even determine the TYPE of the intruder (ROV, surface-fed Diver, scuba diver, etc) and give a very accurate range and position. I've seen them in action and they are seriously impressive bits of kit.
Acoustic comms don't travel faster in water than radio does in air- in fact they're orders of magnitude slower (somewhere in the region of 1500m/s, compared to 300,000,000m/s for radio in air.
What an acoustic signal DOES do, however, is actually travel through the water. Radio has a horrendously short range in water- basically zero unless you want to get into some serious maths, then you can squeeze out some range in certain circumstances- whereas ELF acoustic comms can propagate relatively slowly (though still faster than most jets- the speed of sound in water is ~4x the speed of sound in air, so a plane would have to go Mach 5 to overtake this signal!) through hundreds or thousands of miles of water.
And the higher the frequency, the shorter the range but the more information you can encode onto the wave in a given time (for example, at ~30kHz using RPSK you can encode >1kbit/s and transfer it 3km through a water column). ELF would be useful for sending more code at a slow manual speed, but over hundreds or thousands of miles. It's also harder for equipment to get a good quality lock on the source of an ELF signal unless you've got very complicated, specialised equipment or multiple widely-spaced listening points. Whereas a 35kHz signal can be pinpointed to a few mm from kilometers away (my personal record with this kit is a 4mm window for error at 3000m- using just sound!) using just the one, man-portable transceiver.
What happens if you put a non-ferrous material that interrupts the vibrations of the 'metal conductor'?
I mean starting with wrapping the metal at a point somewhere in the middle with a soft rubber wrap, or
using a rubber gasket along with either a non metallic connector or a metal with different harmonics.
I would also suspect that if you used plumbers tape on the threading that too would cause interference.
I'm sure there are other ideas on how you could also defeat this...
transformer coupling → #
Developed as a joint project by NASA and IIRC the University of North Wales.
The target was looking at some way to handle problems like the rotating joint on the solar arrays of the ISS needing both high power and telemetry channels.
Off hand they were talking of of power transfer in the 100Kw range and data rates in the Mbs range (both with significant capacity for improvement with the high efficiency of transformer coupling.
Transformer coupling only works for a distance of a few wavelengths. Once you are in the far field, you get a wave which needs an electrical component which cannot form in a conductive material.
Further more Eddy currents will greatly attenuate the magnetic fields at high frequencies long before that.
If you think about the problem, the answer is obvious:
unable to use electrical connection
unable to use magnetic connection
unable to use radio waves
Just about all that leaves is audio and mechanical movement. Ramp up the data-rate and reduce detectability/annoyance by using ultra-sonics, using the structure as a mechanical transfer.
Simple really.
Just wait for the foam rubber based (vibration damping) faraday cages to appear.
the people behind this (http://www.sciencedaily.com/videos/2007/0409-metal_rubber.htm) rubbing their hands with glee- it's conductive and it's rubber, so it'd work as (or at least augment) a Faraday cage AND damp out high frequency noise!
With the right business guys, this could make them very wealthy.
Using a combination of Ruby LASER rod and probably piezoelectric crystal* it created a wave they were calling a hypersonic sound (because it traveled faster** than sound in any media that transmitted it.) They wanted to use the effect for inside the egg egg scramblers and death rays and so forth.
Last I heard of it was being used as the plot device for some spy kills spy TV episodes (Man from UNCLE used it once.)
As far as it transmitting power; the little goody that powers your florescent light in the back of your laptop screen works much the same way .
*firing into a Sapphire? I think I remember that.
**Obviously not a common compression wave, possibly the same sort of tech they worked up down in Sarasota Florida in the 70s.
I don't have the slightest were I found out about all this, I remember there used to be something called a library and vaguely remember reading something there.
if I wanted to stop anything being transmitted via power cables I would make an isolated supply
3 options spring to mind
option 1
take the mains, rectify & smooth and filter it
then feed the output of that into an internal inverter
if I wanted to be really nasty to anyone trying to pick anything up off the mains I would make it a square wave driven inverter (which should throw out lots of hash)
option 2
M-G Set (http://en.wikipedia.org/wiki/Motor-generator)
basicly an electric motor coupled to a generator.
these were used heavily in military aviation for creating the higher voltages used in the radio systems but are more than capable of being scaled up to run larger loads.
option 3
Diesel generator in a secure compound
ferrite will only filter out high frequency stuff (otherwise you couldnt use it on 50hz mains) the hardest thing to filter would be a low speed data transfer being done increasing and decreasing current draw on the mains at (maximum transfer speed would be 100bps and it would be very susceptible to interference) but it would get through ferrite untouched and likely get through an inverter since that would pass its increased load on to the outside world
The mog-gens in aircraft are used to produce 3-phase 400 Hz power for avionics. That's the relentless whine one heard in cold war surveillance aircraft. We also used them in the ground support facilities for the same purpose -- 60 Hz single phase in, 400 Hz 3 phase out. Big, heavy, and not particularly. efficient
Mo-gens are also used as a type of UPS -- a big heavy flywheel keeps the generator part spinning while a diesel generator starts up.
Way way back, the spooks discovered how to read decrypted telex traffic in foreign embassies by monitoring electrical noise on the power lines going in to the code room. This varied minutely depending on what character was being set up to print next. I imagine that power lines have been carefully shielded and decoupled ever since this came to light, more than 50 years ago now.
> Get power in and out?
High quality filters. Here's the first relevant hit from googling for screened room mains filter:
www.tesch.de/english/download-fu/mainsfilter-shieldedrooms/a11x73.pdf
100dB+ of attenuation will stop your Ethernet over mains plug from working.
Note the leakage currents though; don't forget your hard-wired secondary earthing.
"The question is, did we patent it? LOL" .... Anomalous Cowturd Posted Thursday 10th March 2011 13:45 GMT
I take it that is sarcasm, or is it irony, AC? :-) Patent spooky technology? I don't think so. One just moves the goalposts every now and then and as one feels like. A little trick learnt/codified in Bletchley huts before most anyone presently working in such fields were even born.
And do you imagine that such works as were leading the field then, stopped after the major hostilities or went deep underground with a cover that they disbanded and work discontinued.?
I was hoping someone had finally managed to prove the existence of axions and at the same time put it to good engineering use [which would be - pass light through magnetic field on side A, some photons turn into axions, pass through wall, where another magnetic field turns some back into photons for detection]. That would have been something, even at 330 bps.
Still pretty good though.
Nah! they keep an eye on patent applications and then issue a confiscation order on anything they like. The owner is given nothing and told he will go to jail if he even talks about it.
Then his idea/tech/solution is given to a defence contractor who sells it back to the military.
If you have a good idea that may have military applications, don't patent it in the UK. Instead go to the EU or US patent offices. That way it becomes impossible for the gov to steal it and give it to thier cronies.
"If you have a good idea that may have military applications, don't patent it in the UK. Instead go to the EU or US patent offices. That way it becomes impossible for the gov to steal it and give it to thier cronies." ....... Jacqui Posted Thursday 10th March 2011 15:40 GMT
The Russia/China/Japan/Pakistan route is another option. Oh, and there's always India and Israel too. In fact, there is an embarrassment of rich pickings for anyone with something which has no need for defense because it is invisibly stealthy in attack. And we haven't even started considering the number of passionate and/or crazy non-state actors out there, with more wealth than they know what to do with, and the will to change the world.
The secret in such dealings appears to be a variation of the nuclear theme ......... sell them the technology for an arm and a leg but ensure that they don't have the triggers ...... but it may be necessary to set of a big bang somewhere politically/financially sensitive just to assure every man and his dog that anything new is a viable global operating device which they need to have remote control of.
TRN, on the web now, I think this might be the same thing.
http://www.trnmag.com/
There was a lot of damn near steampunk tech (LASERpunk) in the 60s most of which went obsolete faster than it could be declassified.
..A mechanical translator using LASERS.
..Mechanical OCR using LASERS.
..Mechanical 3D radar displays; this one did not use LASERS, surprise.
and so on and so on.
Then some stuff that I worked on that is probably still classified.
I can't Google it to be sure without the black (steam or LASER powered) gyro-copters showing up.
Now of course we just emulate everything and have become cyberpunk instead.