Comment by rdtsc | Hacker News Reader

Comment by rdtsc | Hacker News Reader

I think with increased use of drones both for attack and surveillance there would also an increase in anti-drone technology.

Is there any easy way to detect and fight drones? Lasers? Jammers? Iran presumably jammed the drone they captured. Can that be done with a transmitter one can build at home?

Drones will be used more and more by law enforcement agencies, and I think eventually they will come with some (at least at first) non-lethal weapons -- flash grenades, rubber bullets, tazers, spikes for your car tires. Ran the red light? -- better watch out, a drone will be dropping tire spikes soon in front of your car.

In that respect I bet counter-drone technology will become interesting. You know harming a helicopter with real police officers or even harming a K-9 officer is a serious offense. Attempted murder, very threatening. Disabling a flying camera hovering over your head is not there yet. So there is less threat of a harsh punishment. Of course laws will catch up and there will probably be special provisions and penalties for disabling or tampering with drones that go beyond run of the mill vandalism.

Assuming you know the frequency a drone is flying on, it is trivial to jam. However a lot of the more advanced flight control systems (even on hobbyist drones) will have a failsafe that causes it to return to home or similar in the case of loss of radio contact. I suppose even in that situation you could use a GPS jammer to stop that from happening. Of course this would all be highly illegal.

Is a directed EMP beam possible to fry some its electronics. Also presumably if it uses GPS and not inertial systems a GPS jammer might be useful.

[This is just theoretical, don't try any of this it is probably highly illegal]

Hardware for autonomous flight will have to include both GPS and inertial sensors. I suppose an EMP beam could theoretically be used to damage the electronics, but it probably isn't very practical and the electronics could easily be designed to shield against this if it became a legitimate threat.

Assuming you know the frequency a drone is flying on, it is trivial to jam.

Hence they make it hard to know the frequency: http://en.wikipedia.org/wiki/Frequency_hopping

Yep, the vast majority of 2.4 GHz hobbyist RC aircraft do this, but you're still subject to noise floor issues. It might take a heck of a lot of power, but there's no technical reason why this stuff still can't be jammed, and it's not that rare to have signal drop-outs caused by (presumably) unintentional interference.

Powering up a multi-megawatt 2.4 GHz jammer will get you arrested. You are not allowed to transmit in the 2.4GHz band over a few watts (and even then) without a license and the rules are very specific for what you can send (in Australia for example you're not allowed to encrypt that traffic).

And frankly, all the panicky idiots who keep salivating at the prospect of wrecking things makes me glad the rules for radio transmissions are the way they are. Heads off a heck of a lot of problems.

My favorite comment was the user who was so worried about the danger of drones falling on people in Yosemite that he/she would throw a rock to knock the drone out of the sky. Solid logic.

You don't need multiple megawatts. You just need to be louder than the original transmitter. And that's not all that hard, especially if you can use a directional antenna pointing in the direction of the drone.

For frequency hopping radio links, you would need to be louder than the original transmitter on every part of the spectrum the radio is jumping to.

Being 'dirty' is a lot easier than being clean. The bands are typically not all that wide and to mess them up is easier than to be nice. A sawtooth modulator with a suitably high frequency modulating a carrier will disrupt a significant chunk of the spectrum with reasonably little power input. After all you only need to disrupt part of each packet to disrupt the packet. Jamming is a lot easier than getting a nicely modulated signal through.

"In that respect I bet counter-drone technology will become interesting."

How about a net? http://commons.wikimedia.org/wiki/File:Pioneer_RPV_recovered...

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