US prisons want to take them out. Drones, not cats.
The Federal Bureau of Prisons on Wednesday put out a call for information on integrated systems that can detect, track, interdict, engage and neutralize small unmanned aerial vehicles (UAVs) – specifically, those that weigh less than 55 lbs. (25 kg).
It’s not just drugs and mobile phones the bureau wants to keep out, it’s also unauthorized surveillance, it said:
From small devices of less than a pound that can provide unauthorized imagery and surveillance to larger systems that can carry 20 or more pounds of contraband, these devices represent a new and unprecedented challenge for [prison] personnel.
These are the tasks the bureau said it was looking for in a drone detection/termination system, according to the RFI:
- Clean up/attribution of UAVs
A system that could do them all would be great, but a subset might also be pretty sweet, it said.
Just how, exactly, such a system would be able to safely disable drones without having them turn into noggin-crushing meteorites is an open question.
We’ve seen possibilities that include attacking drones with resonant frequency that screws with the gadgets’ gyroscopes.
In fact, there are already sound-related devices on the market for both offensive and defensive purposes: one, the LRAD Corporation’s 450XL, is billed as an “acoustic hailing device” that can be mounted on a vehicle or a tripod and can project a voice message up to 1700 meters.
Then again, there’s also the technique employed by William Merideth: a shotgun and Number 8 birdshot. But that does get us back into the realm of meteors and skull-crushing.
At any rate, the prisons bureau said that the general requirements for an anti-drone system include the ability to handle:
- Operation in mixed-use airspace, where both threat and “friendly” drones may be operating.
- Drone performance that consists of: Flying altitudes from ground level to 18,000 ft. at velocities from 0 to 100 m/sec.
- Highly variable dimensions, but in general less than 4 ft. in their maximum dimensions.
- Drones made from materials ranging from carbon fiber to high-density plastic to light metal alloys and others.
- Both commercially available as well as custom-made UAVs.
- Detection ranges of 1 mile with tracking at .75 miles and kill/interdiction as far out as possible.
- Both command operation as well as autonomous functioning.
- Use of GPS.
- Surveillance target being generally isolated in the middle of an open area with limited ground clutter and other interfering sources such as people and RF. There may, however, be roads where vehicular traffic is moving within the zone of interest.