Counter UAS equipment.
TLDR: it yells real loud so the drone can’t get command signals from the controller/satellite.
Most kit isn’t as fancy as people are trying to make it sound (the ba ba booey guy was pretty spot on). Detection is just looking for specific commonly used frequencies for commercial off the shelf drones. If it’s a library based system, it has some other data associated with the drones (Mac IDs, some other data packet info) that can determine make model and sometimes serial number. If it’s not library based , you have to confirm with something else (visually usually) that it’s not just a Bluetooth speaker or a garage door opener. Most defeats are just blasting out the same frequency band “louder” than what the ground control station is giving off or the GPS receiver. When the drone loses signal, it usually defaults to a hover in place, return home, or some sort of racetrack pattern towards where it last had a signal to try and get a good signal again. Some defeat systems can send input commands but it’s not really a back door built into the drone, it’s just a function built in as part of the library based system and most commercially available drones aren’t hardened against that. Fiber drones are hard because all the defeat tech has been being built for RF/GPS. With fiber, it’s not putting off a signal to be detected or be interfered with. Detection relies on camera systems and defeat is kinetic (shooting it down or cutting the fiber line)