This Hackaday article details a DIY passive radar system built to track aircraft by analyzing existing radio wave reflections. Unlike traditional radar, this system doesn't emit its own signal, instead relying on signals already present in the environment, specifically those used for ADS-B transmissions. The system uses a nine-element Yagi antenna to capture these reflections and a computer program to compare the direct and reflected signals, identifying aircraft.
Pi Pico Rx is a modern electronic project inspired by the crystal radio. Pi Pico Rx, using a Raspberry Pi Pico, an analogue switch, and an op-amp, can create a simple yet capable SDR receiver covering LW, MW, and SW bands, capable of receiving signals from around the globe. The project is still in the experimental stage, with more technical details available in the provided documentation.
