The Drone Dilemma, Part 5: Taking down drones

The interesting thing about technology is that new technology often spawns counter technology. Such is the case with drones as law enforcement is responding with ways to take down drones. In part 5 of our series, we find that technology is not the only answer for downing drones. Birds of prey are also being used.

A new technology uses radio control to take down a drone, known as the DronedefenderTM it is a communications jamming “rifle” that doesn’t fire bullets. Instead, it overpowers the drone taking command away from the pilot. “Targeted” towards restricted air space, the device is good to 1300 feet. The good news is it doesn’t destroy the drone. The bad news is that it can cause the operator to lose the drone. With the penalties of unregistered drones approaching three years in prison and $250,000 in fines, that could be the least of one’s worries. The first article in this series on drones, The Drone Dilemma, Part 1: The Lack of Bandwidth and Signal Strength, focused on a new technology that could keep drones immune from jamming due to ultrafast signal transmission. At the time of this writing, investors still seem more interested in funding incremental software changes over disruptive hardware advances.

Jamming is also being extended to stationary locations such as the Whitehouse. The military has developed weaponry against drone attacks. These weapons either jam the drone or shoot it down. The options for jamming include disabling, taking control, or taking them off course. One weapon that is of interest is the laser. A laser defense system is being developed by a German company, Rheinmetall Defense Electronics. This system will use four, high energy lasers.

Technology is at risk when a drone is shot down. Iran claimed it shot down a US drone in 2011. It was reported that they had reverse engineered the technology. The Pentagon refuted the claim in 2014 saying the Iranian drone was nowhere near as capable.

Other methods have been used to disable drones as well. One singer named Enrique Iglesias snatched a drone out of the sky during a concert. It turns out that this was not a smart move as he ended up in the hospital with a severe laceration. Reports of protestors taking down drones by swiping it out of the sky with a t-shirt also have been published.

One of the most interesting stories has been the use of eagles to take down drones. Birds of prey have long enabled man to pursue game without the use of traditional weaponry. Now the Dutch police are training them to snatch drones out of the sky. With many drones sporting sharp, whirling propellers, there is no doubt animal rights activists will be stepping in on this subject.

As the old saying states, “What goes up, must come down.” As engineers, there is opportunity for new designs in that latter part of that statement. I’m sure the ingenuity of Planet Analog readers will spawn new technologies as time progresses. Or maybe there will just be a similar ending for the drone as there was for the mail delivery robot. As the story goes, it was so obnoxious that engineers programmed it to commit suicide by accelerating down a very long hallway until it broke through the window at the end falling to its death. After all, engineers make for good pranksters. RIP Bob Pease, we picked up where you left off.


  1. Anti-Drone Rifle Uses Unbelievable Tech to Take Down Drones (VIDEO)
  2. New rifle shoots drones out of the sky without firing a single bullet” By Zach Epstein on Oct 16, 2015 at 9:20 AM
  3. Dutch police are training eagles to take out drones” By James Vincent, February 1, 2016 08:32 am
  4. Enrique Iglesias Injures Hand Grabbing Drone During Concert”, BY DANIEL KREPS May 31, 2015
  5. The Drone Dilemma: Lack of Bandwidth & Signal Strength” Scott Deuty, Power, Analog Engineer
  6. , 12/10/2015 08:30 AM EST

  8. New Weapons Spell Death For Drones; The Countermeasure Dance” By COLIN CLARK on October 13, 2014 at 4:42 PM
  9. Lasers And Electronic Warfare To Be Used In New World Of Drones And Anti-Drones,” Nicholas West SEPTEMBER 25, 2015
  10. ‘No way!’: Pentagon trashes Iranian replica of US drone,” no author listed, 13 Nov, 2014 17:32

5 comments on “The Drone Dilemma, Part 5: Taking down drones

  1. Mike@FH
    February 24, 2016

    If Amazon do begin deliveries by drone then it will only be time before someone develops a 'drone-grabber' drone to grab the delivery drone and pull it to the ground so that it's payload can be stolen.

    February 24, 2016

    The two “ideas” presented to bring down drones are mostly unworkable.


    The first, which overpowers the drone's receiver, will work only in the case of non-autonomous craft.  I build multirotor aircraft and the majority of my “fleet” is capable of totally autonomous flight (GPS guided).  I program in a route, which includes position altitude and action, and then flip the switch to AUTO, and from that point on the craft needs no radio signal from anywhere. 

    The typical “failsafe” settings are:

    When flying in MANUAL mode and radio signal is lost – return to the point of launch. So jamming the radio signal or overpowering the drone's receiver would work in this case. But – when flying in AUTO mode and radio signal is lost – continue on with the pre-programmed mission. 

    I normally fly in AUTO mode, since my craft can fly better than I can – especially if it is far away. AUTO mode prevents me from flying closer to a point of interest (that I see by virtue of my on-board camer and video downlink), but nonetheless, it will continue on its merry way. So the 'jammers' won't work.


    And the idea of 'catching' one using large predatory birds is crazy for all but the smallest of toy drones.  Most of my aircraft weigh in the 5-8 pound range.  They have 4 or 6 motors that each can produce at least 1/4HP and each one spins a 12-18″ razor-sharp propeller at around 4,000 RPM.  From the topside (where most birds will attack), there is very little space between the propellers and usually not much to grab onto.  And although there is more to grab from the underside, can you really train an eagle to fly upside down?  And even if something managed to grab it, the drone will 'fight' to stay upright and maintain altitude by virtue of its processor, accelerometers, gyroscopes, and altimiter.

  3. Effective-Technical-Writing dot com
    February 25, 2016

    It sounds like you have made your drone a bit more immune to jamming however signal jamming is as easy as driving a frequency with a highly amplified signal that over drives the original signal.  The first article in this series talks about it.  I'm not saying you're wrong however I would advise caution. 

    It is good that you have a fail safe condition in your drone in case it loses the signal.  Predators are programmed to go into a holding pattern until a signal is reaquired.  

    As for eagles flying upside down, that's how they mate.  Perhaps Google images has some views.  They do grab each other from the upside down position however I don't know if they can be taught to grab objects that way.

    Keep the feedback coming as this is a forum for discussion.

  4. Effective-Technical-Writing dot com
    February 25, 2016

    I'm sure all kinds of counter measures will be created.  Amazon will probably have their own counter measures including a spy cam to take images of the theif.

    February 25, 2016

    Most all UAVs  – Unmanned Aerial Vehicle (I don't like to call them DRONES because of the negative connotation) use frequency hopping spread sprectrum modulation for control.  'this is so that large numbers of radios can be used simultaneously without interference or regard to which “channel” someone else is transmitting on. To accomplish the FHSS communication, each transmitter/receiver pair is “bound” to one another and will not respond to other transmitters in the area. The control frequency is usually (but not always) 2.4GHz and there are 4-8 encoded “channels” that each control a function (throttle, pitch, roll, yaw, mode, etc).  Each channel occupies a position in the sent packet, but there is no defined order.  For that reason, even if you could decode the protocol, you wouldn't easily know which channel did what –  meaning that even if you could somehow spoof the receiver into thinking you were the operator, you couldn't take control of the craft without having it fall out of the sky. 

    And like I said, overloading the reciver with a directed beam of RF will not stop it if it is in AUTO mode.  In the case of loss of signal, the operator can decide the desired action.  A UAV can be programmed to either Land immediately, Return to Launch location, or Continue on with its pre-programmed “mission”.  Like I mentioned, in the case of loss of signal (or jammed radio signal) I have all mine (I have 9 UAVs) set to RETURN to LAUNCH  if I am flying manually, or CONTINUE on with a mission if it is in the AUTO mode.


    I didn't know that eagles could fly upside down, but if one did grab a UAV from the underside, I think it would still find it impossible to bring one to the ground safely.  Those whirling blades are like a lawnmower without a platform – and can do just as much damage.  And unlike a lawnmower, the control system of the UAV will do everything in its power to remain upright and at a given altitude.  Most UAVs work with a thrust/weight ratio of 2-3, meaning that a craft that has a weight of 5 lbs will have a lift of 10 – 15 lbs. So not only would the bird have to grab it when flying upside down, it would have to pull it down all the way to the ground (while still flying inverted).  And then what would it do once it got to the ground? If it let go, the UAV would simply climb again.

    Also, the headline-grabbing photo was of a bird close to a 'toy' quad, like a dji PHANTOM (the little plastic white ones you always see in the news), which are 10 -12″ square. Mine are usually much bigger, with 12″-18″ propellers and a size of 28″ 40″ across.  If an eagle tried to attack one of those (and I have actually had cases where large birds looked like they were  going to attack),  the eagle would be SERIOUSLY injured and my UAV may or may not stay in the air.

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