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
hmmm...maybe some mil spec siesmic detectors cross-zoned with dual beam pirs? whatever it will be it will be very expensive.
You keep talking as if the shape of the area is going to change weekly. Are you planning to move this system around, or are you just really into landscaping. if this is to be a portable system then you have added another headache to your situation.
rg> I would be monitoring outdoor landscaped areas. They could contain
Fact is, we've not been given nearly enough info to make any intelligent suggestions on this.
Perhaps a guard-dog or night watchman would be the most cost effective and practical answer..but who knows?...we're all just guessin'
| > 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. | | | | -- | | | *** Posted via a free Usenet account from
You might also consider seismic sensors. These can be buried in concentric circles (or whatever shapes you like) around protected areas. You can define how to respond to an outer circle violation differently from the inner circle with some systems. These systems are not cheap but they do offer a good deal of flexibility, perhaps more than most surface mounted technologies. They have the added benefit of being totally invisible and undetectable to the intruder.
You have absolutely NO f****ng idea about those devices.
Sure he does... he has Google. LOL.
Have something to add? Share your thoughts — no account required.
Ask the community — no account required