Re: diy microwave alarm

[joe hey <joehey@xxxxxxxxxxxxxx>]

On Thu, 01 May 2014 14:15:28 -0500, G. Morgan wrote:

> joe hey Wrote:
>
>>Hi, I was wondering if there are any (I didn't find any using google) do
>>it yourself descriptions for a microwave perimeter intrusion detector/
>>alarm?
>>
>>From the pictures I've seen of opened up ones, the antennas used seem
>>pretty simple. Electronincs shouldn't be too hard either.
>>
>>Application is for protecting an agricultural area of about 3 ha, bound
>>by 6 straight lines and corners.
>>
>>Has anyone ever come across some useful links?
>
>
> I would just use a CCTV system with motion sensing.

Prohibitively expensive.

>  You can cover huge
> areas with few cameras for that type of use.  Make sure the DVR has
> external contacts to trip whatever annunciation or actionable device you
> are planning to use once something is detected.  At least you'll have a
> picture to go by if someone is stealing fruit!

Why? There is a guard ready to shoot him right away :)

> Are you just trying to be notified if a person is roaming the field?

Yes!

> Why not PE beams along the fence line? Or infrared/microwave combo units

YES! That was what I was looking for: (successful) DIY designs for these.
Or even reverse engineered would be ok.

(What is a 'PE beam'?)

> if you are going to use lots of short-range detectors?  That will
> drastically cut false "alarms".

Again, costs should not become prohibitive.

> Three acres is a lot to cover,

I think the 3 ha (hectares) that I mentioned is even a much larger area
(3 x 100 m x 100 m). So yes, it _is_ a lot to cover, but luckily we only
have to cover the boundaries (totalling about 800 meters).

> and microwave sensors would be way down
> on my list to consider (if they even made the list).  You're looking at
> range issues, false positives, undetected positives, and a general pain
> in the ass all the way around.

Yes, I admit we have a problem :/