If we spam critical EM frequencies drones may fall out of the sky. For example a laser pointer may overwhelm optical sensors, while ultrasonic distance sensors are often used to determine height and proximity to obstacles. Some pilot software may fail gracefully, by safely flying blind and landing gently - but I’m guessing most will fail spectacularly.
> If we spam critical EM frequencies drones may fall out of the sky.
1. Now everybody within X miles hates your guts because phones and wifi are broken and emergency services can't talk to one another and airplanes have to detour while the FCC is sharping their knives.
2. Criminals who don't care about being nice people will just use frequencies you can't/won't jam, perhaps even the ranges that let the guards' walkie-talkies work, as long as the encoding doesn't lead to telltale noises.
A yagi antenna is VERY directional and at these frequencies line-of-sight only.
You are aiming into the air.
I'd say it would be practically impossible to accidentally interfere with cell-phone communication.
This is a realistic counter-attack (and theoretically easy).
I expect savvy criminals won't have too many problems adopting a system where an aborted run causes the drone to automatically divert to a different recovery site, so that the operator has options on how and when they want to try getting it back.
I imagine the ideal location would be one where (A) the drone can sit unattended without being in casual view from passerby (B) it's hard for law-enforcement to set up an ambush (C) someone can walk/drive past without looking suspicious.
Come to think of it, that might be good operation-security even for regular runs, where the drone never returns to the same starting point. That way if someone sees where it came from, they don't necessarily know it will go, and vice-versa.
A path can be reasonably retraced using inertial guidance, if things aren't too windy.
It doesn't need to get all the way home, just far enough away in the right general direction without hitting an obstacle... And most prisons are not surrounded by skyscrapers.
Birds are actually fairly straightforward to evade—you rapidly ascend vertically. If the bird tried to follow, its wings would stall (they can feel this happening and avoid it).
I've had a drone taken down by an eagle. But I've also had larger eagles completely ignore drones coming quite close to them because they don't think it's food or a threat.
Some (most?) prisons are near built-up areas, which means non-kinetic solutions.
- glue-ball cannon
- EMP cannon
- water cannon
- an eagle