[kozak]

I always wanted to try to do this with RF wavelengths like 2.4 GHz.

[awqrre]

Mapping WiFi Signals in 3 Dimensions: http://hackaday.com/2015/02/17/mapping-wifi-signals-in-3-dim...

[fudged71]

I'd forgotten about this project, really loved this!!

[SauliusLukse]

Can be done, just highly directional antennas are bulky and setup needs to be much bigger.