Use of wire loop in fence as a proximity detector (?)

[David Lesher]

Lots of folks have spend lots of money looking for the 'perfect'
fence system. Last I heard, they still resemble Diogenes...

In general, your false alarm rate in inversely proportional
to the probability of detection. The added factor is price;
the more you spend, the better the ratio....

 

[David Lesher]

Google on triboelectric cable.

It was around when I did a study for Uncle Sam in the early 90's.
I'm sure they've improved it since then, but I'm also sure it's no
Magic Answer yet, either.

No alarm system ever built has human judgement....