LEO-enhanced BDS-3/INS tightly-coupled integration in urban environments

The complementary characteristics of the long-term stability of Global Satellite Navigation System (GNSS) and the short-term high-precision performance of inertial navigation systems (INS) have led to the widespread adoption of GNSS/INS integrated navigation system. However, in scenarios with poor GNSS observability, the integrated navigation system fails to perform normal measurement updates, resulting in degraded positioning accuracy. Considering low Earth orbit (LEO) satellites can enhance satellite observation geometry and provide redundant observations for users, this study proposes a LEO-enhanced BDS-3/INS tightly-coupled integration approach and conducts performance evaluations across multiple scenarios. The results demonstrate that, under semi-occlusion, overhead occlusion and surrounding occlusion conditions, the minimum positioning performance improvement reached 15%; The performance is further enhanced after applying the Unscented Kalman Filter (UKF) algorithm.