Re: Perimeter Intrusion Detection
Hisler
> A few people have asked about perimeter intrusion detection. So, here
> is my take on it.
>
> The first thing you need is a fence to keep small animals out of it.
> Otherwise, you will get so many false alarms from small animals that
> you won't want to respond to all of them. It doesn't have to be a big
> fence. A three foot chicken wire fence would work for that.
>
> You of course could have dogs who may are may not bark at intruders.
> Next, you have the cheap mechanical noise makers such as trip wires
> attached to noise makers. Not very effective, but you do get what you
> pay for. They are very easily defeated.
>
> Then you get into the expensive electronics. You have infrared beams.
> You have e-flex cable which picks up vibration. This you could mount
> on a fairly high fence or underground. You have microwave intrusion
> detectors Then you have motion detectors such as are used on outdoor
> lights.
>
> Now, lets discuss how to defeat the electronics. Infrared beams are
> easy. Simply don't break the beam. Go over it or go under it. E-flex
> counts vibrations over a given period of time. Motion detectors count
> the number of movements over a given period of time. So, you can
> simply walk through them if you walk slow enough. The beam is very
> narrow near the unit, so if you use them, mount them fairly high and
> point them out. Be sure to overlap the coverage areas.
>
> Microwaves have a fairly large beam in the middle of the vector.
> However the beam really isn't much higher than the height of the unit.
> They are very easy to go over. Overlap all zones of coverage so that
> there are no dead zones where someone can access your units The
> nearer you get to the units, the narrower the detection beam is.
>
> Now, that being said, plan on weather extremes raising havoc with your
> system. The only way I've seen people get around this is to wire
> systems so that two different systems have to go into alarm systems in
> series so that they both have to go into alarm to set off the
> annunciator and even that doesn't work all the time. So, when you
> have high wind, rain, hail, sleet, or extremely low temperature, they
> don't work.
>
> As I said before, if you are talking about a wooded area, you can
> simply forget electronics. The motion of the trees will set them off
> and the trees will facilitate someone simply going over whatever you
> put out.
>
> The idea of natural plant barriers will work for an amateur intruder.
> Someone who knows what they are doing who sees a perimeter detection
> system is not going to take the easy way in. They will go over it,
> under it, or through your hedge of rose bushes. Also, anyone with a
> pair of pliers can go through an electric fence faster than they could
> go through your chicken wire outer fence.
>
> In short, the only perimeter detection system that I've seen that
> really works is a chain link fence with several layers of razor wire
> and two continuous patrols supplemented with continuous CCTV coverage.
> The vehicle entrance points have steel I-Beams mounted across the
> road. Not something within the average survivalists budget and
> nothing screams "There is something here worth trying to take" than
> that kind of a system. Be prepared and ready to defend what's inside.
A problem with microwaves is that they are bad for your health. The
Border Patrol put radar along the border to create a "virtual wall." If
you happen to be an unlucky person who lives or works in an area that is
constantly blanketed with radar then you should be prepared for the
damage to your eyes and DNA that will result. In Colorado, there are
electronic signs that flash your speed as you go through a school zone
or residential area or construction zone. I would imagine that after
repeatedly driving through those zones one has an increased risk of
cataracts. Add to that the body scanners at airports and motion
detectors that turn on lights in rooms and you increase the chance of
broken DNA strands, birth defects for people of child bearing age, etc..
IMHO, the best perimeter warning system is either dogs or geese.
Geese will attack intruders and drive them off with their pecking and
biting. Even chickens make a lot of noise when they sense danger.