I think you're missing the whole 'autonomous' thing here.
There is no signal, and there is no operator.
The US govt has been working on countering autonomous drones for years now.
The Department is mitigating the potential negative effects of unmanned systems on U.S. forces, assets, and installations – at home and abroad. A critical portion of our efforts, particularly in the near-term, comes from improving our defenses, with an emphasis on detection as well as active and passive defenses
https://media.defense.gov/2024/Dec/05/2003599149/-1/-1/0/FAC...
Its been working on countering drones (unmanned systems) for years; most of the drone threat it has been focused on is not autonomous but remotely-controlled. But there is considerable overlap in countermeasures (other than ones that target the control channel of remotely controlled drones.)
What countermeasures exist against a swarm of autonomous drones, other than an EMP weapon?
(Other than CIWS, because nothing like that can be used on land.)
> (Other than CIWS, because nothing like that can be used on land.)
Someone should tell the US, UK, Israel, and Australia (all of whom operate the Centurion C-RAM/Land Phalanx Weapon System) [0] that that land-based CIWS system, and any potential similar system, cannot be used on land.