> equally cheap or cheaper

I doubt it, as D_A's target is stationary (and could be reduced to GPS coords) while D_B's target is moving.

Couldn’t post earlier seems HN is rate limited :/

hardest issue as I mentioned in another comment is detection. Now on using other drones to counter a drone, there are other issues, as I built and tested some before, assuming you got the detection part done. The first one is guidance and correction mid-air, flying manually won’t really be practical due to the need for an extraordinary flying skills, which can’t be relied on in the field, the second part is the speed, you need to ALWAYS make sure the interceptor is faster to catch it up, third is the weight, I disagree about the payload part you mentioned, I have seen videos of light weight drones failing to wreck bigger ones, if you are relying on collision alone. Additionally, the telemetry/video/C&C for the interceptor, if jamming is already in place, your counter won’t work either.

The swarm will require a low latency comms link, centralized or decentralized, if the area is jammed, it won’t work. i have built a self-healing decentralized system using cellular in each drone, but that’s useless if the network is down to start with.

So they might work in a very specific use case, but not an ultimate solution to counter them.

David Suaez in Kill Decision had swarms of small single shot drones with the targeting intelligence of ‘00 camera. Identify a face, fly towards it, fire when close. It was an implementation of quantity has a quality all its own.

At long distances the small cross section of the drone requires tight focusing (expensive optics) or a high power, preferably pulsed laser (expensive laser) or both.

Not impossible but many times more expensive than the drone

The practicalities of using lasers are covered in some depth on the Naval Gazing blog. First part here:

https://www.navalgazing.net/Lasers-at-Sea-Part-1

At very short distances and with a lot of power, perhaps. Despite what we see in movies laser beams diverge. And then with distance it’s harder to track moving objects precisely to hit the same spot long enough to melt it.

At that point might as well spend the money to use a kinetic weapon with basic tracking and ballistic calculations.

Powerful enough laser and accurate enough targeting system is easy to say, but not easypeasy to do. Dumping thousands of Joules on a tiny moving target is much easier to do with explosives.

Lasers imo don't really have IRL advantages over machine guns and rockets, and their line of sight nature is a huge limitation.

Lasers won’t effectively work, it’s a two part equation, detection and targeting. To neutralize a target using a ground-based laser, you need an enormous power, and still it won’t penetrate a high distance/altitude in the sky, environment factors also to be considered. The detection part is even harder, these small 8in drones are almost impossible to detect unless you can hear it, aka it’s over, because they can fly at 250km/h, too small to be visually detected, acoustic sensors will fail to detect them, and radar will miss it as a false negative since it’s the size of a bird. I have seen some systems trying to combine all that to detect them plus AI for flying pattern detection, but they are far from being reliable in practical applications.

> "let alone with AI" what's falling into the AI category here perhaps is the key question, since microseconds counts, and LLM are very slow!

LLMs (Large Language Models) are far from the only type of AI around. It's a pretty broad field, and there are real-time AI systems, for example, self-driving cars, which have the response times you're thinking of. [1]

[1] https://en.wikipedia.org/wiki/Artificial_Intelligence:_A_Mod...

"Jet airplanes for sure are completely safe from small drones."

That feels like a bold and unsupported assertion. Ask a pilot how they'd feel about takeoffs or landings through airspace filled with adversarial drones.

A flock of unlucky geese can knock out a jet turbine, how is this a "for sure" conclusion?

> Jet airplanes for sure are completely safe from small drones.

Until they land then, due to their cost, they become a very juicy target to aim for.

maybe in the air, but I seem to recall the Ukrainians being successful at attacking Russian planes on the ground.