Re: [Discuss-gnuradio] Passive RADAR

[John Clark]

Krzysztof Kamieniecki wrote:

> Eric,
>
> Do you have a presentation you could share with us?
>
> The question is, can you detect a police car's radio from a far enough 
> distance away so that you could slow down before they check your speed 
> with a Laser?
> From what I have read, people seem to think the radio may be too well 
> shielded.
>
> This for educational purposes, of course. 


I was quickly going through the list and this one just happened to catch 
my eye... there are a number of 'police RADAR' detectors
out on the market. There's no need to, execpt for 'educational' 
purposes, created such a detector.

What 'passive RADAR' suggests to me is using the myrad of RF signals 
which are emitted all the time, to then monitor and intripolate
the existence of objects which reflect these emissions.

Back in the ancient days be fore Cable TV, and TV channels were received 
from the air by an antenna, the passing of an aircraft in the line
of signal for a TV channel would induce a distortion of the received 
signal... it was very anoying... but that is the fundamental principle
of 'passive' RADAR. Such a distortion received at various locations 
could then be used to locate the object which was moving through
the signal.