A deeply integrated GBNS/INS system for navigation in multipath environments

The Ground-Based Navigation System (GBNS) utilizing pseudolites (PL) deployed on surface of the earth for positioning shows superior robustness and accuracy than the Global Navigation Satellite System (GNSS) in urban and canyon environments, which is attributed to stronger signal strength, ionospheric-free characteristic, better terrain adaptability, and greater layout flexibility. However, multipath interference is a major cause of degraded navigation accuracy of GBNS. In this paper, we propose a deeply integrated GBNS/INS navigation system that utilizes a newly designed variable-period pre-filter and an adaptive vector tracking loop (VTL) architecture to enhance positioning accuracy in multipath environments. A software platform named multipath environments software platform (MESP) is constructed for navigation simulation in multipath environments, and a hardware-in-the-loop simulation based on this platform is carried out to evaluate effectiveness of the proposed multipath mitigation techniques. Numerical results and comparisons validate the feasibility and superiority of the proposed system scheme, and the positioning accuracy of this scheme is less than 1.5 m under the simulated multipath scenario.