Thread: Tracking a radio signal
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Unread 10-10-2009, 21:14
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Re: Tracking a radio signal
Quote:
Originally Posted by Don Rotolo View Post
Drop the "robotics"

The Ramsey kit is the size of a textbook (plus antennas), you need a radio receiver for the frequency of interest (you pick the size) and a power source (ditto). I could fit it all into a Cheerios box (but the antennas would poke out) with room for breakfast.

3 or 10 over a square mile as PoC is doable, but scalability will frustrate you even at the hundreds level. The only way around that is a fixed (land-based) antenna network, which doesn't sound practical here. (A friend's company does exactly this, providing equipment location within a hospital. Handy if you need that <equipment name> NOW to save a life)

Research Spread Spectrum, Alan's comment is absolutely valid and when you get past the PoC stage allows for scalability.

(Here's a thought experiment for you: Imagine instead that each device chirped an audio tone, and your 'antenna' was a microphone. How many chirpers before you can't tell one from another? Repeat with chirpers on any of 500 random frequencies (=spread spectrum). Now how many?)

By the way, the Ramsey kit is just an "antenna", you can easily connect up a spread spectrum receiver to it as well.
Proof of concept is all I need for now.

So using this DDF kit I will be able to point, within 22 degrees, towards the beacon with the strongest signal strength? How would I go about decoding the signal then, another directional antenna pointed in the approximate heading? What happens if there happens to be two or three beacons there? I feel like the DDF guiding the directional antenna doesn't provide enough resolution in case there are two beacons in that heading. Can I use the DDF kit to both find the direction of the radio and decode anything incoming?

Thanks
Mike