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Why Detecting Drones Is a Tough Gig 227

Posted by timothy from the if-you-see-something-it's-too-late dept.
An anonymous reader writes with a link to some interesting commentary at Help Net Security from Drone Lab CEO Zain Naboulsi about a security issue of a (so far) unusual kind: detecting drones whose masters are bent on malice. That's relevant after the recent drone flight close enough to the White House to spook the Secret Service, and that wasn't the first -- even if no malice was involved. Drones at their most dangerous in that context are small, quiet, and flying through busy, populated spaces, which makes even detecting them tough, never mind defeating them. From the article, which briefly describes pros and cons of various detection methods: Audio detection does NOT work in urban environments - period. Most microphones only listen well at 25 to 50 feet so, because of the ambient noise in the area, any audio detection method would be rendered useless at 1600 Pennsylvania Avenue. It is also too simple for an operator to change the sound signature of a drone by buying different propellers or making other modifications. It doesn't take much to defeat the many weaknesses of audio detection.
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Why Detecting Drones Is a Tough Gig More

Why Detecting Drones Is a Tough Gig

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  • Are they warmer than a bird? Maybe heat detection?

    • Re: (Score:2)

      by careysb ( 566113 )

      They are controlled by radio which can be detected.

      • That's what the author says as well, he's obviously selling a product based on RF detection of drones. He claims 1400 foot detection ability, also with the ability to determine the GPS location and altitude (presumably the RF signal from the drone would have that information), as well the location of the operator and the unique drone ID. He glosses over radar, but it seems that radar could be built to identify drones with a reasonable accuracy, although I suppose that birds would cause some amount of fals

      • Re:Just wondering (Score:5, Interesting)

        by rthille ( 8526 ) <web-slashdotNO@SPAMrangat.org> on Thursday May 28, 2015 @06:01PM (#49794813) Homepage Journal

        What about an autonomous drone which is just flying to certain GPS coordinates and then detonating? Or even just using inertial guidance and image processing?

      • They are controlled by radio which can be detected.

        That will only find you the pilot, which is not a bad thing, but it's not the direct threat at this point..

        • They are controlled by radio which can be detected.

          That will only find you the pilot, which is not a bad thing, but it's not the direct threat at this point..

          The pilot would be someone who is being blackmailed to do this. He doesn't know who is blackmailing him, just gets the instructions and the drone.

          • Re: (Score:3)

            by 0123456 ( 636235 )

            The pilot would be someone who is being blackmailed to do this. He doesn't know who is blackmailing him, just gets the instructions and the drone.

            Why do you think the person targeting the Killer Drone even has to be in the same country, let alone the same city?

            There is no solution to this problem that involves restricting drones, because that won't stop the bad guys. The only solution is to ensure the Killer Drone can't get to your high-value target.

      • Re: (Score:3)

        by Chas ( 5144 )

        They are controlled by radio which can be detected.

        Yes and no.

        Some higher end models and drones allow you to record and re-execute a series of maneuvers. That pretty much destroys any possibility of interference with a remote controller.

        So, you get measurements of the area you're going to attack.

        Head out to a field and mark off a route.

        Get a viable flight pattern down and record it.

        Go out, setup, let the drone loose.

        Execute the arranged flight flight path.

        Walk away.

      • They are controlled by radio which can be detected.

        Why would I need to control it? I'd program it with a path and actions and it would execute them in radio silence.

        It could be set up with on-line remote control to fly it in manually then upload a program and disconnect the radio. Ie fly it up to the edge of the detection network, survey the location, plan a flight path to get to the objective as safely and reliably as possible, upload the program then disconnect the radio and the drone performs its recon or attack run. This is not science fiction.

        You can't

  • essentially, as of Right Now, drones will avoid and evade at will (of controllers).

  • Detecting Drones (Score:5, Insightful)

    by bezenek ( 958723 ) on Thursday May 28, 2015 @05:45PM (#49794723) Journal

    I assume detecting the RF signature of the transmitter controlling the drone is the best way.

    Of course there are these problems:

    1. There are many signals on the bands used for RC.

    2. It is possible to build an autonomous drone.

    3. In these days of software defined radio, people can spin up non-off-the-shelf, non-standard radio control systems.

    • Re: (Score:2)

      by nbauman ( 624611 )

      I assume detecting the RF signature of the transmitter controlling the drone is the best way.

      Of course there are these problems:

      1. There are many signals on the bands used for RC.

      2. It is possible to build an autonomous drone.

      3. In these days of software defined radio, people can spin up non-off-the-shelf, non-standard radio control systems.

      Hedy Lamar solved this problem. http://www.google.com/patents/... [google.com]

    • Re: (Score:2)

      by Drew M. ( 5831 )

      I assume detecting the RF signature of the transmitter controlling the drone is the best way.

      Of course there are these problems:

      1. There are many signals on the bands used for RC.

      2. It is possible to build an autonomous drone.

      3. In these days of software defined radio, people can spin up non-off-the-shelf, non-standard radio control systems.

      Won't work.

      Nearly all current RC transmitters operate using frequency hopping on the 2.4Ghz wifi band. Try telling it apart from someone's phone scanning for wifi access points. Also the long range RC transmitters like EZUHF and Dragonlink that can do 10+ miles use frequency hopping on the 433MHz HAM radio bands, and you'll find it nearly impossible to detect those either without picking up a ton of HAM radio transmissions from far away.

    • I suggest a multilayered approach.. RF jamming, Signal detectors, GPS jamming as well as physical barriers (nets, trees, fences etc). Couple that with a vigorous response to folks flying these things where they shouldn't and the bulk of the problem goes away...

    • Re: (Score:2)

      by kesuki ( 321456 )

      easy, lasers.
      laser detection grids are cheap, real, and practical.
      they are long range, the only downside is you need a camera to detect if it's a bird or a drone.

      • And then what do you do when you find it's a drone?

        If the answer is "shoot it down" there are severe unintended consequences. A teenager pointed out to me that people would fly drones in there and post the best "drone gets shot down" videos on youtube. I think his explantion used the phrases "cool" and "really cool" several times.

  • It *might* be possible to use an overlapping LIDAR system to pickup on small flying objects. The number of sensors required and the systems integration required would be an enormous task though.

  • RF only works if it's controlled (Score:3)

    by mveloso ( 325617 ) on Thursday May 28, 2015 @05:55PM (#49794785)

    These days you'd set a waypoint, send your drone off, and drive away. There's no RF to speak of, unless you're live-streaming it over LTE.

  • The typical multirotor "drone" is necessarily built very lightweight; the electronics and motors are not typically shielded much at all. The brushless motors emit stupid amounts of RF energy due to unshielded motors, multiple banks of ESC's covered by nothing but heatshrink, etc. It shouldn't be particularly hard to spot a fast moving, localized source of RF noise at frequencies typical of multirotor motors.

    Then there is heat. The ESCs and motors are HOT. Again, mass must be minimized so there is no e

    • Personally I don't think concentrating on the detection problem is the best approach. We can jam, and we can put up barriers and reduce a lot of the risks with very low cost. We already have RF direction finding capability which could be deployed to pinpoint not only the drone but the pilot's location, it's a little costly, but it's out there and would be nearly off the shelf. Trying to build a RADAR or IR sensor to hone in on the drone is a nice idea, but high cost, low reward.

      • Re: (Score:2)

        by Tailhook ( 98486 )

        I don't think concentrating on the detection problem is the best approach

        Yeah, well word #2 in this story's subject is "Detecting," so I went with that. Silly me.

        not only the drone but the pilot's location

        Detecting the "pilot" is actually the hardest part. $200 buys a programmable autopilot that will drop a UAV on any GPS coordinate the batteries can reach — sans pilot. Signals can come from any radio system, including ubiquitous ones like cell towers, so good luck finding that needle in the urban haystack.

        • The self piloted drone doesn't get to it's destination w/o a GPS fix. Short range GPS jammers are off the shelf, *easy* use, and not expensive.

          Remember, I'm saying that detection is down on my list of things to develop, that other things have a better cost/reward and are based on existing technology.

          • Re: (Score:2)

            by Tailhook ( 98486 )

            Good luck jamming inertia [rcgroups.com]

            • Good luck jamming inertia [rcgroups.com]

              Which is why you put up GPS jamming and physical barriers too. Inertial nav is only accurate over short distances, unless you have some external way to calibrate your nav system and can remove the various bias issues caused by vibration, temperature changes and other things that cause changes in the gyros (mechanical, laser ring or otherwise). Usually inertial nav's need to be calibrated, and they do that with GPS (or some other system like LORAN) in order to maintain enough accuracy over time.

              Nothing is

      • Except a lot of drones can now autopilot their way to GPS way points. Set it and forget it, no RF control needed.
        • Did you miss the part where I said we'd jam GPS in the general area of the lawn? Really, you just provide false signals and you can pretty much deflect the drone on GPS autopilot away from it's intended target. Easy to do, off the shelf hardware exists.

  • It's not about detection... (Score:4)

    by bobbied ( 2522392 ) on Thursday May 28, 2015 @05:58PM (#49794795)

    It's about being able to deflect them and prevent them from doing bad things.

    Sure, it's easier to deal with something you can detect in the first place, but if you can effectively block them by putting up barriers, physical and electronic you will have succeeded in your primary goal. So here's my approach..

    1. Do your best to detect them, use sound, video and detect the RF signals emitted by the device and the pilot.

    2. Erect physical barriers that are not visible to the operator or the device. I'm thinking there is a LOT you can do with simple fishing line in this regard, but I'm sure a lot of tall trees would serve an excellent purpose too. Put up an obstacle course.

    3. Put up electronic fences using short range GPS and WiFi jamming around the "protected" area. You can effectively reduce the ability of a drone to find it's way around and make it impossible for it to be remotely controlled.

    4. Concentrate your efforts on finding the PILOT. They will likely have an RF transmitter in their hands, so it shouldn't be that hard, unless the drone is self guided (which is why you jam GPS and provide physical barriers).

    5. And Finally, if you do detect something flying where you don't want, come up with some non-lethal ways of bringing it down. You don't need to fire anti-aircraft guns at it, there are ways I can think of which wouldn't present much risk to people, but would be effective in bringing down your average hobbyist's drone.

    So I say again, detection is but a small piece of the total security puzzle here, and trying to use audio detection is about the LAST way I'd try it...

    • Re: (Score:3)

      by Lehk228 ( 705449 )
      paintball autocannons should do it. not great if you happen to be the driver suprised by the bottom half of the trajectory, but a lot better than .50 cal rifle rounds

  • Easy detection method #48:

    (1) Send out a large electromagnetic pulse

    (2) If it falls out of the sky, it was a drone

  • Why not use cameras instead? I'm not talking about motion detecting ones, which are not going to very reliable, but what about color detection? Most drones stand out distinctly from the sky they're flying in, and you can see glints of light and such from them. You could also simply have human surveillance watch out for them - they tend to be pretty good at telling birds from drones. Machines aren't replacements for humans at everything, you know...

  • ... some techniques [geekwire.com] for dealing with anoying objects buzzing around.

    Just think of a drone as a big mosquito.

  • http://xkcd.com/1523/

    The more I think about this, the more I like it.

  • IANAE (Biologist not an engineer) but since drones are light, the motors can't be well shielded. Appears to be a common problem, at least with readily available commercial stuff.

    http://www.rtl-sdr.com/rtl-sdr-running-adsb-on-a-quadrocopter/

    • Re: (Score:2)

      by guruevi ( 827432 )

      The problem with detecting drones is they don't use specialized stuff, so a windshield wiper motor might as well give the exact same signature as the drone motors. Same goes with RF, GPS, ... Unless you build a physical foil bubble, nothing will keep them out.

  • So, what you're saying is that if someone builds a drone with RF shields on their motors, with hyper-quiet rotors, GPS only autonomous nav, and perhaps an invisibility cloak system they too can evade the drone-police? Thank you, good sers!

  • http://slashdot.org/submission... [slashdot.org]

    http://slashdot.org/submission... [slashdot.org]

    http://slashdot.org/submission... [slashdot.org]

    Because Slashdot is pulling the wool over your eyes.

  • When it comes to drones we have a hell of a lot more to fear from the ones coming out of Pennsylvania ave than the ones flying over it.

  • Audio (Score:3)

    by jmv ( 93421 ) on Thursday May 28, 2015 @07:49PM (#49795357) Homepage

    Audio detection isn't nearly as broken as the article pretends. Sure if all you have is a single mic, then you have no hope. OTOH, with multiple mics, you can *localize* sounds, which means you don't need to recognize the sounds of a drone, just realize that there's some noise coming from something in the air where there shouldn't be anything. With a microphone array, you can actually pinpoint sound sources much weaker than ambient noise. It's certainly not trivial, but within the realm of what's realistic (assuming there aren't simpler solutions).

    • Detection of a drone is much like viewing the sky. It's nearly impossible to spot something.

      Unless there's a RF tag, standard audio config (common prop pitch), visual tag, or something that the vendors add to their drones and is a well known... i.e. a standard, the only way to detect drones are by intelligent multisensor systems. Humans are a great example... and that means time consuming, very expensive and very complex. And they'll (like humans) still have false positives on order of 20% or more. Currentl

  • I don't buy that Audio can't be used. (Score:5, Informative)

    by rahvin112 ( 446269 ) on Thursday May 28, 2015 @07:57PM (#49795395)

    I just don't buy that audio can't be used. With an array of high quality microphones spread over an area fed into a software radio and some pretty hefty computing power you should be able to look for the rhythmic audio that your typical copter type drones will generate. Because even if they change the size and shape of the rotors all that does is change the frequency not the amplitudes you will see from the rhythmic action.

    With some proper math and the right computing power you should be able to identify drones pretty rapidly with fourier analysis and the same microphone array could use Doppler effects to calculate position, and the directional vector. Combine this with some systems to double check such as heat, RF and conventional high band doppler radar and you should have a system that will get 99% of the drones and even provide targeting to a shoot down type system.

    The key here is you need some pretty dam good microphones spread over a pretty large area feeding into a pretty massive computer array. It wouldn't be cheap or easy. The easy thing is use a doppler radar system that cross-checks it against RF emissions to eliminate birds. But IMO the best system would use all three, high band doppler radar, RF emissions and audio (and maybe even heat). With three cross checks you should be able to get pretty good accuracy.

  • I see a point where nets will go up for a while(probably after an attack). But they will be so ugly that there will be relentless pressure to take them down. Then they will have "pop-up" nets. But they won't work and the nets will go up one more time.

    Then some genius will come up with a solution and the nets will go away.

    But we are all taking about little quadcopters and whatnot. But there are many many types of contraptions that will come along with drone technology. Gliders, missiles, planes, darts,

  • Audio detection (Score:3)

    by Catmeat ( 20653 ) <mtm.sys@uea@ac@uk> on Friday May 29, 2015 @11:44AM (#49799921)
    Audio detection does NOT work

    I'd be inclined to modify that statement, and say. "Audio detection does NOT work, now".

    Each rotor of a quadcopter is going to emit sound that depends on the number of prop blades and the prop speed. The four rotors will emit at frequencies that are almost but not quite the same, The four frequencies continuously shift by minute amounts as the control system adjusts power to stay stable in the air.

    The quadcopter therefore has a very distinctive sound signature. This signature is out there, waiting to be detected, if the money can be found to develop the technology to do it.

    Presumably if that happened, there would be a push for stealth quadcopters. But that's another kettle of fish.

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