Micro-Doppler Encoding for Long-Range Drone Monitoring

The massive deployment of small drones in urban airspaces calls for an immediate development of safety monitoring systems. Active solutions, such as live location reporting, are currently in use but heavily depend on continuous data connectivity, highlighting the need for reliable passive alternatives. Here we demonstrate a novel solution to tag the drone blades with electromagnetic stickers. Being driven into rotary motion, those stickers generate object-specific micro-Doppler signatures, which are interpretable by a surveillance radar from a 5km distance, while an untagged drone is barely seen from several 100s of meters.