Re: Ultrasonic Sensors

[Nomen Nescio <nobody@xxxxxxxxx>]

Stanley Barthfarkle said:

>The key here is that you're trying to protect a narrow, curving strip of
>perimeter area, and don't want any gaps. (in other words, spot protection
>won't work) A reliable technology that provides proper catch performance
>while eliminating false alarms in an outdoor area is going to be quite a
>feat. If someone comes up with a viable, real world solution, and not just
>an idea on paper, I'd love to hear about how they did it.

A buried cable system would work.  Two coax cables with intentionally leaky
shields establish a radio field between them.  A human body within this
area affects the field, much like a radio's reception can be affected if
you grab onto the antenna.  Warning:  this stuff isn't even remotely cheap,
and it requires trenching, obviously.  I would not consider this a DIY
project.

- badenov