Two-Dimensional Real-Time Direction-Finding System for UAV RF Signals Based on Uniform Circular Array and MUSIC-WAA

• Published in: Drones (Basel) Vol. 9; no. 4; p. 278
• Main Authors: Zhu, Jizan, Fan, Kuangang, He, Qing, Ye, Jingzhen, Fan, Aigen
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.04.2025
• Subjects: Accuracy; Agricultural production; Algorithms; Antenna arrays; Antennas; Arrays; Azimuth; Cost effectiveness; direction-finding; Drone aircraft; Hovering; Localization; Low altitude; Methods; Mobile communication systems; Monitoring; Music; MUSIC algorithm; Neural networks; Privacy; Radio frequency; Radio signals; Real time; real-time tracking; Search process; Security; Signal classification; Signal processing; Software; Tracking systems; UAV monitoring; uniform circular array; Unmanned aerial vehicles; weighted average algorithm; Wireless communication systems; China
• ISSN: 2504-446X; 2504-446X
• DOI: 10.3390/drones9040278

To address the growing security risks posed by unauthorized unmanned aerial vehicle (UAV) activities, this paper proposes a real-time two-dimensional direction-finding (DF) system for UAVs based on radio frequency (RF) signals. This 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 the computational complexity by over 99.9% at a resolution of 0.1° (from 3,240,000 to 1200 spectral function calculations), enabling real-time estimation of the azimuth and elevation angles. The experimental results demonstrate an average azimuth error of 7.0° and 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 capabilities. 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 the elevation sensitivity due to the UCA’s geometry, this work establishes a practical foundation for UAV monitoring, emphasizing computational efficiency, real-time performance, and adaptability to dynamic environments.