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Comment by nullnilvoid | Hacker News Reader

> Let’s not forget that DJI has software which limits the abilities of the drones based on the pilot’s location. For example, DJI has established that airports are no-fly zones. However, there are some ways that drone pilots can bypass this measure and fly without restriction from DJI.

DJI is going really far on this. They already have pre-installed software which restricts drones in no-fly zones. Even more, they are putting out a bounty program to that. I heard that there are some special electrical guns which can shoot down drones. It might be useful to deploy these in no-fly zones.

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I don't know - the idea of someone who has done a week's "security training" running around all that expensive, critical ground and airborne communications & navigation equipment with a weapon capable of blasting out EMP signals makes me more than a little nervous...

No matter how expensive the "gun" is, you cannot really direct an EMP wave and restrict it like a traditional borescope weapon. All it will take is for someone firing it across an ILS transmitter array at a drone on the other side, and the airport loses their Cat II landing capability just as the airport gets socked in.

Using a phased array you can "lens" a signal fairly effectively. Aside from this, you could use multiple transmitters that are fairly low power on their own, but in a combined and targeted shot could deliver a knockout blow to a drone.

from what I've heard, the 'guns' are just signal jammers

The problem being that in order to effectively 'jam' a signal far away, antenna theory requires that a fairly significant proportion of that radio energy must be directed out the back of the 'antenna'/gun. Right into the person firing it.

That's also ignoring the fact that if the signal to a drone is lost, it's more than likely to fall out of the sky like a ton of bricks.

> That's also ignoring the fact that if the signal to a drone is lost, it's more than likely to fall out of the sky like a ton of bricks.

Consumer drones typically have well-defined and behaved signal loss behavior, which (for DJI ones at least) is even fairly configurable. Though quite often that behavior involves gaining a substantial amount of altitude (at least by default), which at an airport is actually probably worse than dropping.

I don't see why the signal has to go out the back. Otherwise dish-type antennas couldn't work. And those TV aerials would work as well pointed 180 degrees away from a signal as straight at it, which isn't true.

It's based on the antenna design. These 'jammer' devices aren't dish based; they're designed after Yagi-Uda style antennas, in the format of a 'rifle' that the user points at the drone. The radiation pattern for them is exactly as I described. [1]

[1] https://www.electronics-notes.com/images/antenna-yagi-radiat...

Signal-jacking and gps spoofing is the only cost-efficient and scalable way to bring these things down. The word gun really mangles the reality of counter-drone solutions

This machine disables drones.

http://images.sscentral.org/reviews/cps2000_00.jpg

Advanced research technology from the 90s, no doubt. Abandoned due to legal issues. Perhaps it's time to bring it back.

I don't think it's very viable around aiports.

Unless the operator is going out of his way to use a critical frequency as carrier it should actually be relatively trivial to signal-jack the drones, assuming you do it in a narrow beam (thus that you know its position) rather than blanketing an area.

> gps spoofing

That's the part that seems unadvisable near an airport.

Yes, there are plenty of approaches being made to develop such systems that can take down rogue drones.

Privacy violations using drones are another issue that will promote the development of such guns/systems.

Here's a great article that mentions one such system that can hijack drones mid-air: http://www.whatafuture.com/drone-hijacking-device-takeover-t...

Wouldn't a (easy?) solution for a bounty hunter be to exploit a security vulnerability in the drone to track the drone & user?

Or DJI could track these drones themselves from the mothership, uploading the day's GPS history every time they call home... not sure if/why they don't already do this. Would eliminate much of the need for a bounty.

Couldn't they send a drone to dock with the mothership, upload a virus that filters down to all the child drones, set off a nuclear bomb and then escape quickly enough to watch the pieces fall in a fiery wreck to the runway?

"Good morning. In less than an hour, aircraft from here will join others from around the world. And you will be launching the largest aerial battle in this history of mankind..."

> I heard that there are some special electrical guns which can shoot down drones. It might be useful to deploy these in no-fly zones.

The issue is scale. These guns can likely be deployed for big events etc but how do you effectively protect the airspace around airports, powerplants, or other critical infrastructure with such devices?

> how do you effectively protect the airspace around airports, powerplants, or other critical infrastructure with such devices?

Use cameras, acoustic sensors, and RF receivers to detect a drone's presence, and use a phased array antenna to shit some appropriate jamming signals in its general direction.

Your local electronic warfare military contractor should be able to set you up with all the equipment you need for such a system.

Airports are not usually places that radio jamming equipment is tolerated.

I've read about training birds of prey to kill drones, seems dangerous for the bird to me though.

https://youtu.be/YiinhvBCXE8

I have that drone or a variant, it's very light and small.

instead of sending jamming signals, they could deploy a bunch of "bouncer" drones along the perimeter to knock down the unwanted drones. don't know if its going to be very effective, but at least it will be fun to watch. XD

"The Drone Wars"

Joke aside, is not far from being a real tactic, deploying the so-called "defender" drones, which are guided by a autonomous system, fed by an array of sensors around the perimeter.

I can see myself developing such a system.

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