On Fri, 13 May 2005, Dave VanHorn wrote:

>> On Fri, 13 May 2005, vasile surducan wrote:
>> 
>>> You need a laser protected perimeter, and if it's only for caws, then
>>> maybe will be to expensive, it require acumulators, radios and laser
>>> beams.
>> 
>> And nice weather. What's wrong with microwave again ?
>
>
> Rain, wind, Snow, Ice, changes in humidity in the air blowing across, thermal 
> layers in the air...
> And microwave interference.
>
> I used to do that sort of thing for a living.

Do you realise what kind of laser you'd need to cut through those 
conditions ? It would double as perimeter fence (loo the bright 
li...fzzzt).

A relatively low frequency (~1296MHz) beam works well over a few 
hundreds of meters in any weather.

Peter
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