Seeing the world in radio waves with the QuadRF

The QuadRF is an open-source, phase-coherent four-channel software-defined radio (SDR) built around a Raspberry Pi 5 that makes radio direction finding accessible to hobbyists. It features four antennas operating in the 4.9-6.0 GHz range, an FPGA for processing, and can be networked together to form larger phased arrays. The standout feature is an "RF camera" that visualizes detected radio signals at 30 fps and can overlay them on video feeds, enabling users to see and track radio sources like drones.