On Wed, 17 Sep 2014 01:07:03 -0700, mike <
ham...@netzero.net> wrote:
>> ...snip....
>
> You need a temperature difference that moves.
> Under normal conditions, flora is the same temperature as the surrounding
> area. Movement should not be detected...unless the motion of the
> flora masks, then unmasks a hotter or colder region.
Used to be in the Security Industry. Very familiar with almost every
detector but the new ones that actually 'smell' an intruder and recognize
a human. And, can be placed around a location, then you go in later and
pick up your units, go through the data and determine time of day, how
many, and where they went. Don't even have to do this real-time anymore.
Anyway, I'm very familiar with the nuances of designing ultrasonic,
microwave, and IR motion detectos. In addition some types you might not be
familiar with: one that is very obtrusively a visual blight, using 10kHz
electric field androwas and rowas of interlaced send/receive conductors
all for perimeter security; and the less obtrusive one [invisible] like a
cable placed in a zig zag pattern just under the surface of the ground to
detect an intruder walking over it [picture a carpet pad type thingy; and
a perimeter security using parallel 'very leaky' transmission cables that
launches high frequency energy above the surfaceto detect motion of an
intruder. But ALL these still require some processing to determine whether
the disturbance came from an intruder, and what type, or is something else
going on, like gophers digging around. We referred to all these sensors
as, "Fai weather Detectors", because they always worked fine in fair
weather.
When I lived in a super urban area, I once put the 10kHz 'fence' small
section on the inside of a downstairs wall along an unprotected drive. One
night it went off, I went out to discover four very drunk sailors looking
for the tattoo parlor. I had to tell them that was South 600 block, not
the North 600 block, and they all toddled off but less boisterous.
After living in an urban area, I found the best [to keep Ms happy] was to
put in cameras that look AVERYWHERE, and be able to switch them into the
TV screen to 'look around' if you hear something. Her hearing is
incredible! Some details of her hearing ability are astounding. At least
with cameras she can 'look' around, safely.
> ..snip...
> Would also be interesting to know if the bats are consciously
> triggering the light, or if the light is a happy accident of
> their normal foraging behavior.
I do not know. I do know the birds have learned that I fill the birdbath,
so when it goes empty, they'll come around to the office window, opposite
side of the house, and land on the window sill to get my attention [and
glare at me] then when I go around to the breakfast bay windows where the
now empty birdbath is, the bird will stomp around inside the empty
birdbath glaring at me, and if I say nothing just stand there, they fly up
to the window, sit on the ledge look at me, look at the empty birdbath,
look at me, back and forth; as if to say, "Don't you see our birdbath is
empty!? So are gonna fill it?" Then when I go out and fill it; they'll sit
in the trees and chirp loudly, don't know if that means, "Thanks." or
"Where have YOU been?"
> An alternative is to use the cameras for motion detection.
Although possible to do, I still always set all 8 cameras for constant
recording, so I don't miss anything, just in case.
> There are many variables to consider.
> For me, I determined that a sign in the front yard saying,
> "I don't have a big-screen TV, but my neighbor does,"
> would go a long way to prevent being burgled.
>
> A simple motion sensor light says, "It might be risky to
> come here, go next door."
Rodney Dangerfield had a routine about preventing his flat being
burglarized. Somthing about putting a note on the door saying, "I'm
inside, no need to rob me" only to come back and find everything gone and
a note saying, "Stopped in, couldn't find you, so I borrowed a few things."
> I've got several cameras. Just can't imagine that having
> a fuzzy picture of a ski mask stealing my stuff...and my
> camera...would be much help.
>
Picture shouldn't be fuzzy, need a better camera. Turns out that even with
fuzzy images and masked people; someone who knows them can recognize them.
That's why they post those videos on TV News, because someone who knows
the perp will recognize them and turn them in [if really heinous crime]