Two-Dimensional Real-Time Direction-Finding System for Uav Based on Radio Frequency Signals

To address the growing security risks posed by unauthorized UAV activities, this paper proposes a real-time two-dimensional direction-finding (DF) system for UAV based on radio frequency (RF) signals. The system employs a six-element uniform circular array (UCA), synchronized HackRF One receivers, and a hybrid algorithm integrating the multiple signal classification (MUSIC) method with a novel weighted average algorithm (WAA). By optimizing the MUSIC spectrum search process, the WAA reduces computational complexity by over 99.9% (from 3240000 to 1200 spectral function calculations), enabling real-time azimuth and elevation angle estimation. Experimental results demonstrate an average azimuth error of 7.0° and an elevation error of 7.7°, for UAV hovering distances of 30-200 m and heights of 20-90 m. Real-time flight tracking further validates the system’s dynamic monitoring capability. The hardware platform, featuring omnidirectional coverage (0-360° azimuth, 0-90° elevation) and dual-band operation (2.4 GHz/5.8 GHz), offers scalability and cost-effectiveness for low-altitude security applications. Despite limitations in elevation sensitivity due to UCA geometry, this work establishes a practical foundation for UAV monitoring, emphasizing computational efficiency, real-time performance, and adaptability to dynamic environments.