Electronic Distance Measurement 1

[phildi]

Hi, I'm a newbie to engineering and wondered if anyone new of a hand held electronic distance measuring device. The device would need to measure up to 500 meters and may possibly need to operate on multiple frequencies. The idea would be that there would be a target that I need to measure the distance from, but there might be multiple such targets in the surrounding area (hence the need for multiple frequencies). The target would listen for a particular frequency and then return a signal to the hand held device for the distance to be calculated. Does anyone know of such a device on the market at the moment or how best to implement?

Many thanks,

Phil.

 

[Higgler]

There is another thread going now with similar data in the electronic forum.

http://www.eng-tips.com/viewthread.cfm?qid=126043&page=1

kchiggins

 

[IRstuff]

What is this preoccupation with radar?

Use a laser rangefinder; they're cheaper, have extremely tight beams and have more than adequate range resolution.

TTFN

 

[bmccps]

Phildi,
Just ran across your post. I have a similar need and was wondering if you had any luck?
BTW, would your targets be stationary or mobile?

Bmccps

 

[biff44]

Yes there are systems that will do this.

 

[bmccps]

biff44,
Could you share some info/links on some systems that you are speaking of?
Thanks,
bmccps

 

[nbucska]

Max distance is 500m. What is the min and accuracy?
Max measurement time?


<nbucska@pc33peripherals.com> omit 33 Use subj: ENG-TIPS
Plesae read FAQ240-1032

 

[BrianR]

Accurate time delay (distance) measurement by radio is best done using a transmitter modulated by a maximal length pseudo random sequence. This is not too difficult and is the same technique as used by GPS. A 10 bit sequence at a 5MHz chip rate can be correlated to better than 1m and down to a few mm if you get serious about it.

Perhaps GPS would do your job.

 

[biff44]

No, but I can sell you a system.