Revisiting 2D Frequency Scanning Arrays for Low-Complexity 3D Positioning in Spacecraft and IoT Applications

Determining the position of a target in 3D using a radar system provides several benefits over cameras, lidar and other sensors. Applications like spacecraft rendezvous rely on reliable target detection and 3D position, irrespective of light conditions. While phased array antennas and MIMO signal processing can be combined with radar architectures to provide 3D imaging information, they require additional hardware that increases system complexity and can become costly to verify. In this work, we propose a low-cost 3D radar positioning system based on a passive 2D frequency scanning antenna and low-cost PlutoSDR hardware. We establish the performance envelope of the PlutoSDR when used as a pulse compression radar. Finally, we validate the system through a 3D drone-based radar measurement campaign, demonstrating its attractiveness as a low-complexity solution for spaceborne or Internet-of-Things 3D imaging radars, as well as a low-cost radar technology demonstrator platform.