RF Distance measurement

Hello everyone, I´m working on a project that consists on measuring distances between cyclists wirelessly. I thought about sending short distance RF pulses and then measuring the distance depending on the strength of the signal, the stronger the signal, the closer they are. Is there a simple way to measure the signal strength with Arduino? Would it be precise?

Thank you in advance

Signal strength is highly unreliable for this, to the extent that ti's quite useless.

Check out some "follow me luggage" projects to see how they do it. Similar problem. It's a hard one.

One way to use radio waves for this task would be to use Loran C or an SRN-12 receiver and LOP ( Lines Of Position ) type setup.

The other way would be to use GPS and tiny++ GPS library's calculate distance method; which works pretty good.

I assume OP is thinking of cyclists cycling in the same group, which is too little difference in location for GPS to work well. More like collision warning kind of system.

igortoko: Would it be precise?

Nope, exactly the opposite.

So not precise as to be useless.

Signal strength depends on polarization, multipath interference, reflections, obsctructions in the line-of-sight, and front-end desensitization due to strong nearby frequencies. Its hopeless for estimating distance unless you have clear line of sight, no metal around, and calibrated stationary antennas. Otherwise expect an order of magnitude or more of distance fluctuation.

Time-of-flight is another RF technique you could investigate, there are new systems using UWB that might be usable.

And differential GPS is a possibility of course.