[Robotgroup] Triangulation

[vkonradi]

Yea, the speed of light being approximately 1 ft/nS makes it darned difficult to get a cm resolution.  You can get position deltas at this resolution using microwaves and measuring relative phase, but absolute positioning is impractical.

The speed of sound makes measurements quite practical.  If you want to set up a pinging sort of arrangement, ultrasound 32 KHz is good for 60 ft or so (total distance, i.e. 30 ft round trip if you do a reflecting pinger).  You don't have to use ultrasound of course, audible sonic will go even farther.  And ultrasound is just another noise to those with higher hearing bandpass.  Another interesting aspect is that radio at the speed of light (or light at the speed of light) can be used as a trigger, giving you essentially perfect synchronization of multiple sound sources.

Just some thoughts,

Vadim