home made tracker and shooter.possible?

hello.need help in making a home made tracker and shooter.suppose there is a rectangular compound(4 walls) and this tracker is on the ground(say in the middle).a friend of mine(whoz in the neighbourhood) flies a helicopter or a RC aircraft into this compound of mine.outrite intrusion!:P...this tracker SHOULD detect this intruder and fire a home made rocket at it.given that the height of this intruder is 3-4 km but it CAN intrude from ANY direction.the tracker should track it ,lock it and shoot it down.how to do all this..how to prepare whole of this system.thanks alot.have been thinking on it for about 4 months now.still unable to come up with something WORKABLE and easy to BUILD?

orksecurity6 years ago
Nothing is going to be both workable and easy to build.

You would need to be able to not only detect the object's direction but also distance, direction of motion, and speed, so your projectile hits where it's going to be rather than where it was when it first appeared. And if it's maneuvering, you need to update all of that rapidly and frequently.

Meanwhile, you need to avoid "false positives" -- blowing leaves, birds, cats...

Doable? Sure. How much money and computing power and video triangulation and..... are you willing to throw at it?

Then there's the safety issue. Anything you fire, if it misses, is going to come down somewhere else. Ain't no way you're going to be able to do this in suburbia with a rocket. Even a water cannon (safer suggestion) would get Really Loud Complaints the first time you splash a neighbor.