Counter-UAS

Counter-UAS is the umbrella for everything a force does to defend against unmanned aircraft: detecting them, deciding whether they are hostile, and defeating them when necessary. It is a layered problem rather than a single weapon. Detection typically combines radar tuned to small, slow targets; radio-frequency sensing that listens for drone control links; electro-optical and infrared cameras for confirmation; and acoustic sensors as a cheap gap-filler. Each sensor class has blind spots, so serious systems fuse several.

Defeat mechanisms split into soft kill and hard kill. Soft kill attacks the drone's dependencies — jamming its control link, corrupting its satellite navigation, or taking over its protocol — and is preferred where falling wreckage is a hazard. Hard kill destroys the aircraft with guns, missiles, interceptor drones, nets, or directed energy, and is preferred against fast one-way attack drones that may not respond to jamming at all.

The economics drive the doctrine. A defender firing a six-figure missile at a drone costing a few hundred dollars loses the exchange even when the shot works, so the field is preoccupied with cost per engagement. That pressure explains the current interest in electronic warfare, high-power microwave, and laser systems, whose marginal cost per shot approaches the price of electricity.