this post was submitted on 09 Mar 2024
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These flying IEDs can be defeated with some simple radio jamming. They will fall out of the sky without a remote control signal.
So, I haven't played with them, but even commercial, off-the-shelf DJI consumer drones have the ability to return to some location if they lose link, so they're gonna have at least GPS in there. You can jam that, but they've got accelerometers, and you can't jam that. They shouldn't drop out of the sky even if you can manage to jam things.
It looks like DJI drones have frequency-hopping spread spectrum support, too. So you have to jam all frequencies that they're using, since you don't know which they're using at any given instant. For consumer hardware, it probably doesn't matter much -- nobody is jamming you, so you sit in your little assigned piece of spectrum, have a handful of channels -- but in a war, you can probably expand the frequencies you use, use a huge chunk of the spectrum, if need be.
There are also some forms of jam resistance that AFAIK are not being exploited -- beam-forming or directional antennas.
Both Russia and Ukraine have a pretty strong interest in using electronic warfare against drones, and the fact that both are still using a lot of them seems like a pretty good argument that they can't currently successfully stop them via electronic warfare.
And even if you can jam signal when it gets really close to the target, if you have a second drone watching -- which it looks like Ukraine and Russia often are, from the videos I see, maybe to do damage assessment -- you can probably stick a laser designator on those, if they haven't already, use it to guide the weaponized drone in.
Another quick off-the-cuff improvement: the drone feeds being sent today contain a lot of unnecessary information, more than is required for a human operator to guide them in. The less information that needs to make it through, and the more you can afford to cut out and use on redundancy in transmission, the more-jam-resistant the thing is. You can fall back to a unreliable-channel mode if need be for the last bit of the approach.
Here's a satellite source image. That's lossily-compressed, JPEG, at 510,254 bytes. It's pretty, but if you already know what you're looking at and are trying to just ram it, you don't need anything like that much information.
Here's the same image after I've run a Laplace edge-detection on it, denoised it, run a threshold on it (you could probably use a simple heuristic to select the threshold, but even if not, it'd be fine for the operator to manually choose a threshold), converted it to 1-bit, and then PNG-compressed it. That resulting frame is enough to keep identifying the objects in the image, enough that if you could see that frame, an operator could hold it on-target, and it's only 30,343 bytes, about 6% the size.
Then you can use the newly-free bandwidth to send forward error correction information -- some folks here may have used it in the form of PAR2, popular in the piracy scene -- so that if any N% of the data makes it through, the frame can be reassembled. Now it's a lot harder to jam.
And that's an off-the-cuff approach that took me about 2 minutes just using the tools that I have on my system (GIMP and PAR2) and zero time trying to improve on it. You figure that if you pay someone who actually specializes in the area to bang on this a bit, you can probably get something rather better.
I have nothing to add here, I just wanted to say thank you for these interesting details. An upvote didn't feel like enough.