Slashdot Mirror


Sounds Can Knock Drones Out of the Sky

angry tapir writes: Next week at the USENIX Security Symposium, researchers at the Korea Advanced Institute of Science and Technology (KAIST) in Daejon, South Korea, are presenting research into knocking drones out of the sky using directed sound waves. They target a component crucial to every drone's ability to fly: its gyroscope. "A gyroscope keeps a drone balanced, providing information on its tilt, orientation and rotation, allowing for micro-adjustments that keep it aloft. Hobbyist and some commercial drones use inexpensive gyroscopes that are designed as integrated circuit packages." For some drones, the gyroscope and its housing have a resonant frequency that's within the audible spectrum. By targeting the drone with sound waves of that frequency, the gyroscope will begin to generate erroneous data, leading to a crash.

120 comments

  1. Cheaper in KY by Anonymous Coward · · Score: 5, Funny

    Cheaper to get an armed kentucky redneck drunk to bring one down.

    1. Re:Cheaper in KY by Opportunist · · Score: 2

      Yeah, but it's probably more legal to use a subwoofer than a shotgun to keep some pervert from looking at your daughter.

      --
      We used to have a Bill of Rights. Now, with the rights gone, all we have left is the bill.
    2. Re:Cheaper in KY by LessThanObvious · · Score: 1

      No, no. We must have a more complex solution. People who know nothing about guns have to many irrational fears. They will be much more comfortable with a sonic gyro-disruptor.

    3. Re:Cheaper in KY by Anonymous Coward · · Score: 2, Informative

      I'd rather use a jammer. It's much harder to track back to you that way.

  2. Not surprising by LaurenCates · · Score: 4, Informative

    It's also been established that sound can put out fires.

    http://physicsworld.com/cws/ar...

    --
    Some people don't believe in fairies. I don't believe in The Patriarchy.
  3. Not all gyros are mechanical by amalcolm · · Score: 1

    I guess this would not work on optical gyros?

    --
    Time for bed, said Zebedee - boing
    1. Re:Not all gyros are mechanical by jabuzz · · Score: 3, Informative

      Yeah but you are not going to have a ring laser or fibre optic gyroscope in a consumer "drone". It is going to be a cheap MEMS gyroscope, not something that costs thousands of dollars.

      Apart from anything else I suspect that optical gyroscopes need things like export license. Just take a look at the of example ring laser applications on the wikipedia page. It includes things like Trident missiles and a large range of military aircraft.

      In fact a little further Googling shows gyroscopes that are advertised as "Non-ITAR", which should tell you all you need to know.

    2. Re:Not all gyros are mechanical by TrentTheThief · · Score: 2

      Since you can buy fiber optic gyroscopes on Alibaba for under USD$20, I think issue of US-centric export controls is moot.

      This entire attack mode is now a worthless endeavour given this publicity. Anyone with the inclination can modify the case to prevent resonation.

    3. Re:Not all gyros are mechanical by rwise2112 · · Score: 4, Funny

      I guess this would not work on optical gyros?

      It will if you generate the sound with something, say, like a RPG.

      --

      "For every expert, there is an equal and opposite expert"
    4. Re:Not all gyros are mechanical by PolygamousRanchKid+ · · Score: 2

      I guess this would not work on optical gyros?

      No, to take out drones with optical gyros, folks will be using light wave guns, instead of sound wave guns.

      If you give MacGyver two fistfuls of pen pointer lasers, duct tape, chewing gum, and a Wonderbra, he will MacGyver you an array laser cannon that will be able to take out an optical gyroscope drone. And a lot of other things that don't have optical gyroscope drones.

      --
      Schroedinger's Brexit: The UK is both in and out of the EU at the same time!
    5. Re:Not all gyros are mechanical by rjune · · Score: 4, Funny

      Number 4 bird shot also has a sound that be effective against drones.

    6. Re:Not all gyros are mechanical by flink · · Score: 1

      I guess this would not work on optical gyros?

      No, to take out drones with optical gyros, folks will be using light wave guns, instead of sound wave guns.

      Maybe you could combine them... some sort of "wave motion gun"...

    7. Re:Not all gyros are mechanical by kelemvor4 · · Score: 2

      I guess this would not work on optical gyros?

      No, to take out drones with optical gyros, folks will be using light wave guns, instead of sound wave guns.

      If you give MacGyver two fistfuls of pen pointer lasers, duct tape, chewing gum, and a Wonderbra, he will MacGyver you an array laser cannon that will be able to take out an optical gyroscope drone. And a lot of other things that don't have optical gyroscope drones.

      Are you kidding? He could defeat a stealth fighter with all that equipment! Too much.

    8. Re:Not all gyros are mechanical by MobSwatter · · Score: 1

      Number 4 bird shot also has a sound that be effective against drones.

      Not very sporting though, one shot and the fun is over. I rather like the idea of the use of light and sound though, because you can torture the operator that pissed you off for a bit before taking it down.

    9. Re:Not all gyros are mechanical by budgenator · · Score: 2

      I'm not sure anybody knows but it's highly plausable that an optical gyro resonating at an audio frequency would be just as disabling.

      --
      Apocalypse Cancelled, Sorry, No Ticket Refunds
    10. Re:Not all gyros are mechanical by TheCarp · · Score: 1

      > Since you can buy fiber optic gyroscopes on Alibaba for under USD$20, I think issue of US-centric export controls is moot.

      You would think that since you could transmit RSA in an email and international implementations already existed, they would have become moot for those purposes long before they did.

      --
      "I opened my eyes, and everything went dark again"
    11. Re:Not all gyros are mechanical by TrentTheThief · · Score: 1

      Yes, but I believe you missed my point.

      US ITAR only covers exporting materials manufactured/created in the US. Therefore, any consumer, virtually anywhere in the world can obtain a cheap fiber optic gyro for their consumer grade UAV without concern for the United States's continued irrational paranoia about losing a mythic technological edge.

      On an related note, in this case, the ITAR regs reduce market share for US manufacturers and nothing more.

    12. Re:Not all gyros are mechanical by TheCarp · · Score: 1

      No I think you missed my point.... these issues are fundamentally not only the same but, center around the same regulations. Back in the 90s you could obtain, anywhere in the world, RSA code. Yet it was still restricted the same way.

      This is a long standing pattern of stupid which has not appreciably changed in more than 30 years. You should, in fact, expect it.

      --
      "I opened my eyes, and everything went dark again"
    13. Re: Not all gyros are mechanical by jfeldredge · · Score: 1

      For that matter, you could take out most hobby-scale helicopter drones with just the bubble gum, if you could aim it accurately enough. A wad of bubble gum hitting anywhere on the drone would probably unbalance it enough to bring it down, particularly if it hit a rotor.

  4. Rover by A10Mechanic · · Score: 1

    Not sure if it will work for all drones, but it pissed the dog off to no end... But seriously, does inverse square law not apply here? What's the range on this? DNRTFA

    1. Re:Rover by amalcolm · · Score: 2

      Light can be highly directional, yet it obeys the inverse square law.

      --
      Time for bed, said Zebedee - boing
    2. Re:Rover by jabuzz · · Score: 0

      Physics 101 lesson, light does not always obey the inverse square law. Clearly you have never used a flashlight let alone a laser. If you don't understand the conditions required for light to obey the inverse square law it would be better to keep quite rather than spout complete nonsense.

    3. Re: Rover by Anonymous Coward · · Score: 0

      Nonsense.
      Outside the Rayleigh range even lasers obey 1/r2.

    4. Re:Rover by Anonymous Coward · · Score: 0

      Well, it does. https://en.wikipedia.org/wiki/Inverse-square_law#Light_and_other_electromagnetic_radiation

    5. Re:Rover by Anonymous Coward · · Score: 0

      A straight light or sound beam in a medium of constant impedance is not a solution to Maxwell's equations or sound propagation. And while the inverse square law does not apply in the near field, it does in the far field, which for applicable sound frequencies is on the order of a couple meters or less, at best.

      And you would think someone who's used a flashlight would have figured this out, considering a flashlight is very far from an ideal Gaussian beam and has pretty easy to see divergence.

    6. Re:Rover by Mr+D+from+63 · · Score: 1

      Not sure if it will work for all drones, but it pissed the dog off to no end... But seriously, does inverse square law not apply here? What's the range on this? DNRTFA

      Those questions are mute. Effectiveness is not a criteria. We are searching for expensive, difficult, and unreliable methods for downing drones.

    7. Re:Rover by Mr+D+from+63 · · Score: 2

      moot! dammit. SMH

    8. Re:Rover by Anonymous Coward · · Score: 0

      They're not mute, you just can't hear them over the noise while you're downing the drone.

    9. Re:Rover by Anonymous Coward · · Score: 0

      Howdy. As others have pointed out, you are wrong. Very wrong. This would not be so upsetting if it weren't for the fact that you tried so hard to insult the poster you were replying to. Try being more civil next time.

      And to use your own example.... try using a flashlight to illuminate a spot on the moon. Doesn't work to well even if you have a perfectly steady hand.

    10. Re:Rover by ImprovOmega · · Score: 1

      Inverse Square is with respect to point sources. Directional sources can carry much further.

    11. Re:Rover by Anonymous Coward · · Score: 0

      Inverse square law applies to all light and sound sources in the far field, where the distance from the source to the far field depends on the relative size of the source and the wavelength. In the far field, directional sources are still inverse-square bound, but instead have a much higher coefficient by sending stuff out in a fraction of a sphere instead of a whole sphere.

    12. Re:Rover by ihtoit · · Score: 1

      uh... yes, it does. ANY radiated energy flux density decreases as an inverse function of the square of the observer's distance from the origin (visualised as a point source). Ergo, with a beam from a laser, the origin is actually far behind the actual source, so for example a laser beam of radius 1mm emanating from Earth (fired parallel to a telescope) to the Moon would be something like 60km wide by the time the reflected light returns to Earth. The simple reason for this is that like a choked shotgun, as soon as the beam leaves the "barrel" (the optical focussing system inside the laser) it (the light beam or the cloud of shot and expanding hot gas) begins to diverge. The breech for your laser is a few virtual km behind the source (the muzzle).

      Shockingly enough, if instead of a laser you used a shotgun on half choke and had enough fast-enough-burning powder to actually reach the Moon, the shot would diverge enough to pass both sides without hitting.

      --
      Political debates have me rolling my eyes so much I think I got optical whiplash. I should sue. - Foamy The Squirrel
    13. Re:Rover by ihtoit · · Score: 1

      inverse square does apply to directional sources, the origin is behind the source is all.

      --
      Political debates have me rolling my eyes so much I think I got optical whiplash. I should sue. - Foamy The Squirrel
    14. Re:Rover by Anonymous Coward · · Score: 0

      uh... yes, it does. ANY radiated energy flux density decreases as an inverse function of the square of the observer's distance from the origin (visualised as a point source).

      No, this would be completely incorrect, as not every source acts like a point source. A high quality laser beam will produce a Gaussian beam, where the diameter is proportional to sqrt(1+r^2), with the minimum not necessarily at the output of the laser. This asymptotically approaches the shape of a point source far away, but closer to the minimum point it is definitely not like a point source behind the laser. How far it will not behave like a point source depends on the wavelength and minimum diameter.

      Something like a 1 mm beam with 1064 nm wavelength will approach a conical shape after a couple meters, and could not be made smaller than ~500 km on the surface of the moon from earth. If instead you fed the laser into the optics of a 20 m telescope, you would be able to get a spot size of ~30 m on the moon, while a spot size twice as far away would be ~50 m, and half as far 23 m, not looking like a cone shape until ~a million km away.

      The same goes frequently for radio antennas, as their size is often comparable or smaller than the wavelength, and in the near field they can be doing all sorts of things that don't look like the far field 1/r^2 drop off.

    15. Re:Rover by Anonymous Coward · · Score: 0

      the origin is behind the source is all.

      Nope. In the near field a non-point source doesn't act follow inverse square at all, regardless of where you try to place the origin. In the far field, where any source does act like a point source, it can act like the origin is right on the source, or even in front of the source.

    16. Re:Rover by RockDoctor · · Score: 1

      Well, at least you self-corrected. Well done! Most people don't even realise that they're making that particular error, and will then queue up to miss their "next greatest homophone" cue.

      --
      Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
  5. Unpractical by Himmy32 · · Score: 5, Insightful

    For this attack is great if you have to identify the model/gyroscope and have done testing to get a value of the resonant frequencies of the gyroscope before hand and send a sound loud enough to disable it. 140 Db causes permanent hearing damage and that only makes it effective to 40 meters. I hardly think a system that deafens everyone in a large radius to take down a drone for the off chance that you even know the frequency to disable a drone is hardly practical. And if like the ones tested in the article you can attach a speaker to the device before hand, I doubt you even need to think about a system like this to disable the drone.

    1. Re:Unpractical by Anonymous Coward · · Score: 0

      While I agree with most of what you say, the following is a moot point.

      . I hardly think a system that deafens everyone in a large radius to take down a drone for the off chance that you even know the frequency to disable a drone is hardly practical.

      Even the summary says that the sound is being directed and not emitted omnidirectionally.

    2. Re:Unpractical by Anonymous Coward · · Score: 1

      Yes, but if you can use a directed speaker array to produce the sound (like the ones mentioned in the article) the off-beam effects aren't that important. This is a proof of concept, not a practical method.

      BTW the word is "impractical", not "unpractical".

    3. Re:Unpractical by Anonymous Coward · · Score: 0

      It puts paid to The Who's hopes to have a quadrocopter-filmed live set if nothing else.

    4. Re:Unpractical by TWX · · Score: 2

      For this attack is great if you have to identify the model/gyroscope and have done testing to get a value of the resonant frequencies of the gyroscope before hand and send a sound loud enough to disable it.

      And Thinkgeek sells or used to sell a TV remote control that had programmed the IR "OFF" code to just about every television system that had ever been sold, and it would blast them all out at essentially the same time.

      If drones become too annoying then people will refine this tech, making the packaging smaller, the directionality better, and the number of frequencies that it can hop-through more extensive and faster to switch through.

      --
      Do not look into laser with remaining eye.
    5. Re:Unpractical by wvmarle · · Score: 1

      The fun of a good LRAD is that you can stand behind it and hear almost nothing.

    6. Re:Unpractical by PolygamousRanchKid+ · · Score: 4, Insightful

      140 Db causes permanent hearing damage and that only makes it effective to 40 meters.

      That is very good. You don't want to take out the drone anyway. Rather the dork who is flying the drone. If you take out the drone, the dork will just buy another one on Amazon, and come back the next day. Drones are cheap now, so that anyone can afford one.

      What you want to do, is to triangulate the control signal, and make a polite visit to the pilot.

      I have been flying RC helicopters for about 20 years now, and I am appalled at the way some folks fly them dangerously in public.

      --
      Schroedinger's Brexit: The UK is both in and out of the EU at the same time!
    7. Re:Unpractical by Hotawa+Hawk-eye · · Score: 2

      Black Hat Guy has the answer. [At least I assume it's Black Hat Guy; in most of his appearances in that comic he's in bed and it would be silly to wear his hat in bed. Unless his girlfriend likes that kind of thing.] Since his noisy neighbor moved away, it's been sitting in his closet; given his personality, I think he'd be happy to modify it for use as an anti-drone weapon.

    8. Re:Unpractical by Anonymous Coward · · Score: 0

      Drones are cheap now, so that anyone can afford one.

      AAHAHAHAHAAHAHAHAHAHAHA...uh...ahem...AHAHAHAHAHAHAHAHAHAH

    9. Re:Unpractical by tlhIngan · · Score: 1

      For this attack is great if you have to identify the model/gyroscope and have done testing to get a value of the resonant frequencies of the gyroscope before hand and send a sound loud enough to disable it. 140 Db causes permanent hearing damage and that only makes it effective to 40 meters. I hardly think a system that deafens everyone in a large radius to take down a drone for the off chance that you even know the frequency to disable a drone is hardly practical. And if like the ones tested in the article you can attach a speaker to the device before hand, I doubt you even need to think about a system like this to disable the drone.

      You can direct sound quite readily through the use of parametric speakers. Heck, you can buy one or two for experimentation (those things come with a warning because in high power mode, they do 110dB).

      Because the sound is emitted as ultrasonic frequencies, it inherits the directionality of the high frequency.

    10. Re:Unpractical by Technician · · Score: 1

      I think enclosing the electronics package inside a re-purposed headphone to cut the sound and provide crash protection would greatly reduce the effectiveness.

      --
      The truth shall set you free!
    11. Re:Unpractical by Anonymous Coward · · Score: 0

      Not only that but there are vacuum sealed gyros that would be unaffected by this. You could even take a standard gyro and vacuum seal it in a container.

      In short, this technique is trivially defeated. The only drones this would knock out are the ones you shouldn't be worried about in the first place.

    12. Re:Unpractical by stackOVFL · · Score: 2

      Annnnd, if you wanted to really get that dork you could just change the frequency to that of the "brown note" https://en.wikipedia.org/wiki/... and let'm have it!

    13. Re:Unpractical by drinkypoo · · Score: 1

      AAHAHAHAHAAHAHAHAHAHAHA...uh...ahem...AHAHAHAHAHAHAHAHAHAH

      If you troll the sale section on hobbyking, and source parts like the control system on eBay, you really can build a small drone for under two hundred bucks. That's including the battery, the radio, and the charger. If you restrict yourself to a certain class of drone you can even use recycled Li-Ion batteries from old laptop packs, and knock another twenty bucks or so off of that. And we're talking GPS waypoints here, not just a toy. And well into the double-digit minutes of flight time. That's sufficiently close to "anyone"

      --
      "You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
    14. Re:Unpractical by budgenator · · Score: 1

      It only has to be 140dB at the drone, several speakers at much lower volumes could easily achieve this through constructive interference. Both the uplink and downlink on these things is usually 2.4 GHz, your microwave oven is on 2.4 GHz, so if it came down to a pissing contest, the oven has the bigger bladder.

      --
      Apocalypse Cancelled, Sorry, No Ticket Refunds
    15. Re:Unpractical by Obfuscant · · Score: 1
      Amazon sells the Adafruit version of TV-B-Gone as a kit, so you get the fun of building something and then the fun of going to the local sports bar during playoff time and getting beaten to a pulp when they realize you're the reason all the TVs shut off right before the final buzzer.

      If you carry one in your pocket, make sure you either have no coins or other metal, or put good insulation around the board. I had one in my jacket pocket one time and wondered where the smoke smell was coming from.

    16. Re:Unpractical by vandamme · · Score: 1

      That would work if the drone used an IR control, and you knew its code. Unfortunately, all the ones I know of use radio waves. Fortunately, those are easy to jam with noise, so the receiver gets no command signal. Unfortunately, that is illegal. Fortunately, by the time somebody phones the FCC and they drive over with a truck to triangulate your signal, you will be long gone with your newly captured drone and there will be no trace of your jammer.

  6. Missing important details... by MagickalMyst · · Score: 1

    I didn't see anywhere in the article about which specific resonance frequencies were used.

    And at 140 db ... I would be more concerned about the damage to my hearing than to the drone.

    --
    Political correctness is really just herd psychology pushed by insecure people who desperately seek social conformity.
    1. Re:Missing important details... by Anonymous Coward · · Score: 0

      I think the missing information is due to there being no magical set number. You'll have to know what hardware the drone is using to even make use of this, otherwise you'll end up having to toss every frequency in the book at it or something.

      (Not practical)

    2. Re:Missing important details... by MagickalMyst · · Score: 1

      Understood.

      However, the article says:

      "Kim's team studied 15 types of gyroscopes from four vendors....Seven of the gyroscopes resonated at their own resonant frequencies..."

      With only 7 they certainly could have included a list of frequencies, or at least a range.

      --
      Political correctness is really just herd psychology pushed by insecure people who desperately seek social conformity.
    3. Re:Missing important details... by Anonymous Coward · · Score: 0

      I didn't see anywhere in the article about which specific resonance frequencies were used.

      It's there. Table 1 of the actual science paper.

    4. Re:Missing important details... by Obfuscant · · Score: 1

      With only 7 they certainly could have included a list of frequencies, or at least a range.

      Page 7 of the paper that is the second link in the summary.

    5. Re:Missing important details... by MagickalMyst · · Score: 1

      Thank you. :)

      --
      Political correctness is really just herd psychology pushed by insecure people who desperately seek social conformity.
  7. And so can fire hoses by HighOrbit · · Score: 4, Interesting

    Well if they are talking about the toy in the picture and 40 meters is the height, a fire hose or pitched base ball can bring it down too. If it is low enough to be brought down by a fire hose then it is too low and a nuisance.

    What would be more interesting is if sound can bring down a more advanced aircraft that relies on computerized gyroscope stabilization like a F-35 from a few kilometers.

    If you were here a bit over a decade ago, you remember these little babies the HERF guns, http://tech.slashdot.org/story... & http://science.slashdot.org/st.... They would probably work on drones (and more). Given the Inverse-square law, I don't remember what the range might be though.

    1. Re:And so can fire hoses by TWX · · Score: 1

      I'm thinking that a consumer-grade pressure washer might be enough. It probably doesn't take that much mass or propeller-fouling to bring down a drone, and if the electronics aren't sealed then the water might find its way inside and short it out too.

      --
      Do not look into laser with remaining eye.
    2. Re:And so can fire hoses by drinkypoo · · Score: 2

      If you were here a bit over a decade ago, you remember these little babies the HERF guns,

      If you were here a bit over a decade ago, you remember that most of the HERF guns were fakes. If you were paying attention, that is.

      --
      "You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
    3. Re:And so can fire hoses by Lehk228 · · Score: 1

      If you weren't on a list before, you definitely are now.

      --
      Snowden and Manning are heroes.
    4. Re:And so can fire hoses by bobbied · · Score: 1

      What would be more interesting is if sound can bring down a more advanced aircraft that relies on computerized gyroscope stabilization like a F-35 from a few kilometers.

      I seriously doubt they use cheap gyroscopes in the F-35... Most likely they have a set of highly accurate and stable laser ring units which could care less about sound waves..

      --
      "File to fit, pound to insert, paint to match" - Aircraft Maintenance 101
  8. Captain Obvious? by areusche · · Score: 1

    It's like these people have never been to an airshow or close to an airport. Of course the pressure from a sonic boom can disrupt a drone. Ok ok so they took it a step further and are using frequency resonance to crash the drone. This sounds more like poor design on the part of the drone manufacturer, similar to the square windows of the De Havilland Comet.

    Next up, American researchers discover that heavy turbulence can disrupt drones paid for by a $350 billion dollar military science grant!

    1. Re:Captain Obvious? by Anonymous Coward · · Score: 0

      A gyroscope is not designed to measure sound pressure, so it is not obvious to the casual observer that a gyroscope might be disabled by a sound. These are not extraordinary sound levels.

    2. Re:Captain Obvious? by ihtoit · · Score: 1

      I thought what killed the Comet was the pissweak wing roots?

      --
      Political debates have me rolling my eyes so much I think I got optical whiplash. I should sue. - Foamy The Squirrel
  9. Ah by Anonymous Coward · · Score: 2, Funny

    The Blue Note of Death.

  10. Guile has something to say! by Anonymous Coward · · Score: 0

    SONIC BOOM!

  11. Whirrr by Anonymous Coward · · Score: 0

    Wub Wub Wub!!!

    1. Re:Whirrr by PopeRatzo · · Score: 1

      "It's good to be the president!"

      --
      You are welcome on my lawn.
    2. Re:Whirrr by ausekilis · · Score: 1

      I'd love to have a dubstep gun. Those aliens will never see it coming.

    3. Re:Whirrr by gstoddart · · Score: 1

      LOL ... oh, man, suddenly I want one. It would make meetings so much more fun.

      Time to spin up a different mix for the rest of today.

      --
      Lost at C:>. Found at C.
  12. First? by Anonymous Coward · · Score: 0

    Do we still do this?

  13. Ahhh! by Anonymous Coward · · Score: 0

    I would just love to see a video montage of drones falling from the sky. Especially if they're being flown by modern entitled assholes. A zoom-in on their faces afterwards would be priceless.

  14. That is, until... by Pollux · · Score: 1

    Drone manufacturers come up with a "sound-proof drone." Then your new hi-techy gun is just a worthless noisemaker.

    1. Re:That is, until... by TWX · · Score: 3, Informative

      As is the case in an arms race.

      Perhaps eventually we'll have air guns firing very fine lengths of tungsten wire to physically foul the propellers.

      --
      Do not look into laser with remaining eye.
    2. Re:That is, until... by drinkypoo · · Score: 4, Insightful

      Perhaps eventually we'll have air guns firing very fine lengths of tungsten wire to physically foul the propellers.

      You don't need anything so exotic; cheap and readily available nylon monofilament will do just fine. But if I were going to use something fancy, I'd use carbon fiber thread.

      --
      "You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
    3. Re:That is, until... by TWX · · Score: 1

      Something too light won't have good flight characteristics, it'll be inclined to slow and deflect as it passes through air. Tungsten might be overkill, but it'd probably still need to be heavier than nylon.

      --
      Do not look into laser with remaining eye.
    4. Re:That is, until... by drinkypoo · · Score: 1

      Something too light won't have good flight characteristics, it'll be inclined to slow and deflect as it passes through air. Tungsten might be overkill, but it'd probably still need to be heavier than nylon.

      I think the ideal would be a CO2-driven pellet which trailed the line... You could get the whole thing to be pretty small and light, ideal for mounting on another drone.

      --
      "You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
    5. Re:That is, until... by Lehk228 · · Score: 0

      If you are going to shoot at it with a pellet gun, skip the hassle of trailing a thread and just shoot it directly with the pellet or BlackBerry or .22LR

      --
      Snowden and Manning are heroes.
    6. Re:That is, until... by drinkypoo · · Score: 2

      If you are going to shoot at it with a pellet gun, skip the hassle of trailing a thread and just shoot it directly with the pellet or BlackBerry or .22LR

      The problem with that is that with many designs, it will take many shots to have a hope of reliably disabling the model. A lot of these things are just a big wad of polystyrene, which can take a whole lot of hits without really caring if they're not really good ones. Then there's the ones made of carbon fiber rods, yeah that stuff is fragile in its own way but if you don't get a solid hit with your pellet you can't expect to do anything good. Props are fragile but there's a substantial chance of a miss there for obvious reasons... unless your projectile is trailing something.

      --
      "You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
    7. Re:That is, until... by TWX · · Score: 1

      That sounds plausible.

      Though we're essentially reinventing the old, "cannonballs tied together with a length of chain" design but in miniature, aren't we?

      I wonder if water with its associated surface tension could be used, if water would itself be inadequate. Use the mass of the water to carry the fibers...

      --
      Do not look into laser with remaining eye.
    8. Re:That is, until... by drinkypoo · · Score: 1

      Though we're essentially reinventing the old, "cannonballs tied together with a length of chain" design but in miniature, aren't we?

      We've got a long way to go before we reach the scale at which classical physics breaks down :)

      I wonder if water with its associated surface tension could be used, if water would itself be inadequate. Use the mass of the water to carry the fibers...

      Now I'm imagining drone-killing silly string.

      --
      "You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
    9. Re:That is, until... by Obfuscant · · Score: 1

      I think the ideal would be a CO2-driven pellet which trailed the line...

      Taser darts trail a wire behind them.

    10. Re:That is, until... by ihtoit · · Score: 1

      Dacron (a polyester-cotton mix) would be perfect, I think. A single strand of Terko Satin (an industrial brand I have a mile of in three ply twist, that I use for fishing mainline and netmaking for snares) has a breaking strain of 25kg and is the same thickness (and about the same weight) as 2kg nylon monofilament.

      A little history: Dacron used to be the preferred alternative for fishing line as opposed silk or cotton (the former of which was not very waterproof unless soak-treated with beeswax, the latter vulnerable to rot), until the cheaper alternative (nylon) became available. That's the only reason nylon is used now: it's cheaper. I love dacron because it's WAY stronger and it doesn't stretch (nylon monofil has a stretch potential of something ridiculous like 15%).

      --
      Political debates have me rolling my eyes so much I think I got optical whiplash. I should sue. - Foamy The Squirrel
    11. Re:That is, until... by vandamme · · Score: 1

      Barrage balloons. Look 'em up.

    12. Re:That is, until... by Lehk228 · · Score: 1

      A tail might work, but bird shot or target shot will work better and be more reliable and be cheaper

      --
      Snowden and Manning are heroes.
  15. Take My Money! by Anonymous Coward · · Score: 0

    Make it hand held and I'll make that a Christmas present to myself! Then, I can go outside and shoot down all the quadcopters the neighbor kids got. BUAHAHAHAHA!

  16. Sounds good by jfdavis668 · · Score: 1

    Sounds real good.

  17. omfg by Anonymous Coward · · Score: 0

    I never thought I'd see a Resonance Cascade, let alone create one...

    1. Re:omfg by ememisya · · Score: 1

      Boss man walks in, in some unknown military institution:

      Boss: -So uh, looks like the drones you wrote the "balance code" for have been dropping out of the sky.
      Programmer: -How?
      Boss: -Someone is shaking the crap out of the gyroscope.
      Programmer: -Well, uh ... maybe we can insulate the gyroscope? Or write some grace period for manoeuvring from the input having a threshold?
      Boss: -Why didn't you think about this before?
      Programmer: -I didn't think it would be subject to a German opera singer sir.
      Boss: -Get to work!

  18. Range by dtmos · · Score: 1

    From TFA:

    [. . .] According to this prediction, the possible attack distance is approximately 16.78 cm using the same sound source that we used for the real-world attack with the maximum volume (113 dB). This attack distance range might not be sufficient for a malicious attacker. However, attackers can overcome this distance limitation by using a more powerful and directional source (e.g., a loudspeaker array) than the single speaker used in our experiments. For instance, SB-3F from Meyersound can generate sound of 120 dB at 100 m, and 450XL from LRAD and HyperShield from UltraElectronics can produce 140 dB at 1 m, which is equivalent to 108.5 dB at 37.58 m. Therefore, the possible attack distance is 37.58 m, if an attacker uses a sound source that can generate 140 dB of SPL at 1 m.

  19. Just focus on it by ITRambo · · Score: 2

    And say "Muad'Dib" really loud. Take you spice first so you don't run out of juice. Only works with blue eyed people.

    1. Re: Just focus on it by Anonymous Coward · · Score: 0

      Die in a Stone Burner fire, you racist jihadist Fremen fanatic fedaykin fag.

  20. Good! by p51d007 · · Score: 1

    Give them to firefighters to knock down these idiots flying them over a forest fire.

  21. Filtering by Anonymous Coward · · Score: 0

    Most amateur drones would not fly at all without the use of heavy filtering,
    usually 20 Hz cutoff. Mine do, anyway.

    As any resonant frequencies will be well above this, it doesn't really matter. There's a lot of noise from propellers to fight all the time.

    1. Re:Filtering by Anonymous Coward · · Score: 0

      Filters are not perfect and such systems/gryos have limited dynamic range. When you start hitting aliasing and clipping problems, signals get a lot harder to interpret, especially if the controller is not designed to do so.

    2. Re:Filtering by Anonymous Coward · · Score: 0

      Yeah, like you can't hear bass over loud flute ..
      Unless your ears are saturated with >130dB sound pressure, frequencies are separable. Pure and simple.

    3. Re:Filtering by Anonymous Coward · · Score: 0

      Unless your ears are saturated with >130dB sound pressure, frequencies are separable.

      The response and saturation point of your ears has nothing to do with the response and saturation point of a particular mechanical system... That said, masking in the human ear is a well known phenomena, where a louder tone of one frequency can hide a quieter tone of another tone. This can happen with less than a 20 dB difference at typical levels, depending on particular frequencies and other factors. The human ear is quite nonlinear in some ways, including intermodulation and shifting of gain to correct for the limited ~50 dB dynamic range of the inner hair cells.

  22. "Drones" by Anonymous Coward · · Score: 0

    It's a mistake to think that all "drones" are multi-rotor aircraft.

    1. Re:"Drones" by ColdWetDog · · Score: 1

      It's a mistake to think that all "drones" are multi-rotor aircraft.

      Yeah, most of the ones I know about work at the office.

      --
      Faster! Faster! Faster would be better!
    2. Re:"Drones" by Anonymous Coward · · Score: 0

      Its a mistake to fight against changes in vernacular. People are dumb and will continue to misuse words until everyone misuses the word so much that it has lost the original meaning.

    3. Re:"Drones" by Anonymous Coward · · Score: 0

      Yeah, no kidding.

      https://en.wikipedia.org/wiki/Lockheed_D-21

  23. Too bad they stopped making these by cnaumann · · Score: 1

    The Agent Zero Sonic Blaster. Destroying drones and kid's hearing since 1960.

    http://www.retrothing.com/2009...

  24. Figures ... by Foobar+of+Borg · · Score: 1

    ... on the one article in which the Moo Cow guy should post (e.g., using cow moos to take down drones, or something like that), he can't be bothered to do so (at least, not yet).

    1. Re:Figures ... by Anonymous Coward · · Score: 0

      he'll be back; his mom is making him clean his room right now.

  25. Not surprised by Huge_UID · · Score: 1

    My wife's farts can knock birds out of the sky.

  26. Sound can kill by Wuahn · · Score: 1

    High decibels can kill fish in a lake adjacent to an outdoor rock concert. A directed sound weapon can quell a riot or liquefy internal organs. None of this is new. Shotguns loaded with "drone shot" are the answer.

  27. Weatherproofing by Anonymous Coward · · Score: 0

    What happens if the gyroscope is sealed in a potted metal box, like most prosumer models?

    The gyro-resonance is well known in the sensor community. The problem is getting any signal/ID to the drone--which is very hard as a omnidirectional flying vehicle, like tracking a fly in the room.

  28. Brown note for Zune powered Drones? by Anonymous Coward · · Score: 0

    Brown note for Zune powered Drones?

  29. So? Use differential gyros by Anonymous Coward · · Score: 0

    Mount two gyros, face-to-face (or belly-to-belly if you prefer) on the controller PCB, now anything in-phase is the external noise.

  30. Re:Read TFA, only some sensors affected by Technician · · Score: 1

    The test data from a variety of manufactures devices show most were not substantially resonant in the tests.

    Due to prop balance in drones, it may be a relatively safe assumption the ones with resonant issues are not used in drones but limited to low frequency applications such as Wii remote sensors.

    --
    The truth shall set you free!
  31. Just use a slingshot by Anonymous Coward · · Score: 0

    A rock and a slingshot can bring down these drones

  32. Sonic Screwdrivers! by djhaskin987 · · Score: 1

    Huh, they really do have a use

  33. ...or you could do it with an air cannon by ihtoit · · Score: 1

    You read that right. One of these: https://www.vat19.com/item/air... will kill a drone from 40 feet. And that's basically a breadbag cannon. A three inch plastic pipe and a can of butane gets you an air cannon with a range of a couple hundred feet. Drop in a tennis ball, you're firing that thing a quarter mile with a kill range of one hundred yards.

    --
    Political debates have me rolling my eyes so much I think I got optical whiplash. I should sue. - Foamy The Squirrel
  34. Watch out for The Doctor... by Anonymous Coward · · Score: 0

    And its sonic probe...er...screwdriver.

  35. Apparently Yelling by Anonymous Coward · · Score: 0

    Not only feels good, but can dispatch an intrusive drone! Just yell really, REALLY loud.