using RF to measure distance 1

[shamone]

Hi, I am trying to measure the distance between a stationary point and a moving point up to at most 1200ft. I think RF is the best(or only way) to do it. Wondering if anybody knows an effective, cost efficient, method of doing this. The distance is not always line of sight either. Thanks.

 

[shamone]

Wow, you nailed it on the first try analog....or maybe not lol

 

[SolderingGunslinger]

Wow! I agree, Analog is dead on.

I thought the device would be placed on the Bull so you could go cow-tipping whithout the needless worry of accidently bothering the bull far from the pasture fence!

I remain,

The Old Soldering Gunslinger

 

[stargate3216]

I think I have an idea. What you do is get the lowest fz osillator you can and plug it into a syn. binary counter. When you press a button it sends the voltage to the counter to start and the tranmitter. Then, when the reciver gets the signal after it comes back it sends the signal to the counter to stop. You then have the counter send to final count to a BASIC stamp chip that you have programed to calcutate the distance. It then sends that to a Binary-to-BCD converter and then to a 7-segment LED display.

 

[shamone]

Nice one stargate, that is pretty much what i have in mind. Except i will use and LCD instead. Gonna get around to it pretty soon. Cheers

 

[VEBill]

Stargate3216 - Congratulations, you've just invented 'The Digital Timer' (but you'd want the highest frequency feasible).

 

[JBender]

MikeHalloran, you just described my EE senior design project! I made 3 receivers, collected delay data from them and triangulated a position. The idea was to locate someone with a "panic buzzer" using sensors on the blue light emergency call poles in many campuses.

The implementaiton of "listening" to a buzzer and timing it to within a few milliseconds proved to be harder than I thought, but I did it! I used a tight bandpass filter to listen for the sound, and measure the time difference between the RF and the sound. But that didn't work very well...

So I repeated the RF and sound at about 2 Hz. I then took my magnitude output signal from the bandpass filter and bandpass filtered that at 2Hz. After a few itterations it gave resonable results. We ended up with a map of campus and a dot following around a person with a very annoying buzzer. Accurate to maybe 5 or 10 meters. We Won best overall project from the IEEE.

 

[MikeHalloran]

Congrats, JBender!

Now I'm wondering if I could pick up the 'bang' and the RF from my lawnmower ... and make it autonomous.





Mike Halloran
NOT speaking for
DeAngelo Marine Exhaust Inc.
Ft. Lauderdale, FL, USA

 

[itsmoked]

If you scew it up, poor kitty...

 

[MikeHalloran]

Think of it as population control for felines.

Alternatives exist.

A friend has a Rhodesian Ridgeback, a big, strong dog with a distinctive textured stripe on her spine. Ridgebacks were bred to hunt lions, so they don't much care for cats.

She doesn't kill 'em directly, though; she field- strips 'em, by peeling back their pelt from neck to tail, leaving them to hobble home without a skin.

Women hear about that, and say, "Eee

http://wwww,

that's awful".

Guys say, "What a cool dog."




Mike Halloran
NOT speaking for
DeAngelo Marine Exhaust Inc.
Ft. Lauderdale, FL, USA

 

[itsmoked]

I'll take two!