GNSS/UWB based indoor and outdoor continuous positioning method

To address the problems that Global Navigation Satellite System (GNSS) and ultra-wideband (UWB) positioning systems have limited range in complex indoor and outdoor environments, and that no single source can obtain continuous and reliable positioning results from outdoor to indoor. In this paper, we investigate the BeiDou Navigation Satellite System (BDS)+GPS/UWB loose combination positioning method, design dynamic indoor and outdoor positioning experiments and static positioning experiments in the transition area, use the extended Kalman filter to optimally estimate the positioning error state, and analyze and evaluate three positioning modes: BDS+GPS combination, UWB and loose combination. The experimental results show that the combination of BDS+GPS/UWB improves the positioning accuracy and extends the range of GNSS-real-time kinematic (GNSS-RTK) in the indoor-outdoor transition area, and the combination of BDS+GPS/UWB improves the continuity and usability of the system from outdoor to indoor positioning compared with each single source.