Direction using radio 1

[astroclone]

This is similar to my ranging using radio post. Since I see that that is not a feasable option what about an object that emits a signal that is picked up by a reciever. My goal is to know the direction to the signal and using 2 or more recievers to triangulate.

I was thinking maybe the reciever could rotate to get 360 deg. coverage and have an encoder so that when the reciever recieves a signal it knows what direction it came from.

Non-rotating would be better since moving parts break. Any suggestions are welcome.
Thank you for your time,
T

 

[melone]

How accurate to you have to be? Could GPS work for your application?

 

[astroclone]

GPS would be ideal, but I am looking at doing this inside a building, like an airplane hangar. I'm not sure how well GPS works indoors, if at all. Accuracy would be ideally 1 to 2 feet, but I can be flexible about that.
T

 

[Baldor]

I just remembered that at this years' OTC(offshore technology conference),one of the companies displayed a location system for rig floor safety. The floor had some kind of grid wires embedded in it, and each worker had a sensor molded into their boots. An operator could look at a display and see where every worker was located.

 

[astroclone]

That's kinda cool....and creepy.

 

[IRstuff]

Wish you had bothered to mention the hangar in the first place, which generally nullifies ANY radio based approach, since the walls of the hangar and things within it will reflect and you'll have multipath up the wazoo.

You should be looking at an optical approach, possibly using arrays of emitters located on the walls or ceiling and an imaging detector with VERY large field of view.

TTFN

 

[AlexKrauska]

See

http://www.arrl.org,

search for fox hunt receivers. some amazing, cheap, effective ideas here. They should do what you want. I seem to recall one that had a circular pattern of 16 LED's on it to indicate the direction of the signal. With three of these you should have the redundancy to find the signal.

 

[rickcappels]

A fellow named Harry Lythall (one of my heros) has published the design of a system like that mentioned by hocage, on his web site. His site uses frames, so this is as specific as I can get:

http://w1.859.telia.com/~u85920178/

Click on "Receiver Circuits" near the top of the frame, then click on "FM DF system".

There is also a tracking antenna (fox hunting type hand-held phased vertical dipoles)

Under "Antenna Projects" click on "VHF Direction ant".

Rick

 

[jtsamuels]

My two cents. The ARRL site is excellent if you are a memeber and is not worth the time if you aren't. Try this site which incorporates ham radio articles as well as direction finding club information.

http://members.aol.com/homingin/

Also, "steering" a radiated signal by controlling the phase of the signal as it is applied to each antenna is easy in concept a pain in practice, though if you get good at it the US Military wants you (or the former Hughes Corporation - the military supplier, not the rock band!) as they have that and it is called phased array radar and is installed on all the Aegis Class Destroyers (

http://www.russell.navy.mil/home.htm)

As for internal reflections within the hangar, a good RDF system will still give a stronger signal towards the original source. You may have to move about a bit or, if this is not practical, install several phased antenna arrays feeding into the one receiver and triangulate ( or at least see if they all point in the same general direction).

Good luck,
Jim

 

[Comcokid]

Astroclone
In answer to a past post where there was a need to track items in a hanger-sized area - I think this was you. You've started several posts concerning ranging and tracking over a short distance.

I just stumbled across a UWB tracking item meant to locate and track assets. Check out the following link and other info at the following site.

http://www.multispectral.com/pdf/PAL.pdf

 

[astroclone]

Comcokid,
That may be exactly what I need. Brilliant.
Now I just need to get the robot zombies to come to life!
T