Roughly speaking, you just need a mobile receiving unit, or multiple fixed receiving units, with a reorientable directional antenna. You find the heading where

Roughly speaking, you just need a mobile receiving unit, or multiple fixed receiving units, with a reorientable directional antenna. You find the heading where the signal has maximum strength from a few points, and then triangulate. There are relatively inexpensive Software Defined Radio devices to enable this sort of thing. See: https://www.crowdsupply.com/krakenrf/krakensdr https://www.crowdsupply.com/krakenrf/krakensdr https://www.rtl-sdr.com/ksdr/ https://www.rtl-sdr.com/ksdr/ Other related discussions here on HN: https://news.ycombinator.com/item?id=28054017 https://news.ycombinator.com/item?id=28054017 https://news.ycombinator.com/item?id=27857290 https://news.ycombinator.com/item?id=27857290