Accurate Multi-UAV Positioning in Complex Environments Using UWB-Aided GNSS/INS Fusion

Accurate localization is critical for the reliable operation of multi-UAV systems, particularly in environments where GNSS signals are degraded or unavailable. This paper presents a tightly coupled GNSS/INS integration approach enhanced with Ultra-Wideband (UWB) relative ranging to improve navigation performance in GNSS-challenged scenarios. The proposed method employs an Extended Kalman Filter (EKF) to fuse inertial measurements, GNSS data, and inter-UAV distance observations, providing robust and continuous state estimation. Experimental results demonstrate that the integration of UWB significantly reduces positioning errors during GNSS outages, maintaining high accuracy and stability compared to standalone INS or GNSS/INS fusion methods. The system shows strong performance in both static and dynamic denial conditions, confirming the effectiveness of UWB-assisted localization for UAV operations in complex urban and contested environments.