Radio Orienteering or “Fox Hunting” Amateur Radio Direction Finding (ARDF) actually just “Transmitter Funding”
Amateur radio direction finding wikipedia
Some Hardware options for Direction finding:
Build it: 2 meter Tape Measure Yagi Beam Antenna – KB9VBR Antennas (jpole-antenna.com)
Fox Hunting – 3rd Planet Solar / KC9ON
Fox Hunt Offset Attenuator – 3rd Planet Solar / KC9ON