Doppler-Enhanced Angle-of-Arrival Estimation for Tracking Autonomous Localization of Errant UAVs
Ching Huei Huang, Wen Ling Chen, Ciao Yu Zeng, Wei Chun Weng · IEEE Access · 2026
With the proliferation of uncrewed aerial system (UAS), ensuring operational resilience under global navigation satellite system (GNSS)-denied conditions as a system-level constraint or denied/degraded signal environments has become a critical security imperative. This paper proposes an integrated autonomous localization framework designed for the detection and tracking of errant uncrewed aerial vehicles (UAVs). Unlike conventional direction-finding systems that necessitate prior spectral knowledge, the proposed architecture incorporates an autonomous blind-signal discovery algorithm that scans and locks onto unknown emitters in real-time. The system architecture features a hardware-software co-design approach: a high-precision dual-axis gimbal—governed by a programmable logic controller (PLC) for full 360° azimuthal and 90° elevation scanning—integrated with a software-defined radio (SDR)-based processing hub. By leveraging a single rotating directional antenna, the framework exploits-controlled signal Doppler frequency (SDF) modulation, effectively extracting spatial information from received signal strength indicator (RSSI) and signal-to-noise ratio (SNR) profiles without the hardware complexity of massive antenna arrays. To ensure high-fidelity angle-of-arrival (AOA) estimation, we implement a comparative robust filtering framework utilizing Savitzky-Golay (SG) and recursive least squares (RLS) algorithms to suppress both stochastic environmental noise and deterministic mechanical jitter. Experimental validation, blending MATLAB-based high-fidelity simulations with field-tested hardware measurements, demonstrates that the system significantly enhances signal-to-noise margins and minimizes angular estimation errors. The results substantiate that this integrated solution offers a low-SWaP (size, weight, and power), cost-effective, and portable alternative for UAV localization in critical defense and public safety operations.