Re: Ultrasonic Sensors

["Stanley Barthfarkle" <sbarth@xxxxxxxxx>]

>I would be monitoring outdoor landscaped areas. They could contain
> ponds, waterfalls, ...
> They will vary in size and shape so there is no well-defined perimeter
> that is consistent from one installation to the next. The perimeter
> will more often than not be finished with stone or concrete rather than
> natural grass and soil.
>
> Infra red barriers would be an option if the shape of the perimeter was
> symmetrical but it will often not be that way.
>
> Per my previous post, I was thinking of trying ultrasonics mounted at
> the perimeter of the inner circle, pointing toward the outer circle. I
> would have to space them close enough so their sensing patterns overlap
> to guard the entire perimeter.



That's going to be a tough one. Never heard of a product that was designed
for what you are trying to do. The automobile backup sensors have never been
used for security purposes that I'm aware of. Once upon a time, ultrasonic
volumetric sensors were used INDOORS for space protection- quite unreliably,
I might add.

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.