关键词: 北斗RDSS, 非合作用户定位, 深度残差网络, 时空网格, 到达时间差

Abstract: The BeiDou Navigation Satellite System has seen global deployment and large-scale application. Consequently, its distinctive short message communication service is experiencing explosive growth. However, actual communication processes involve many non-cooperative users. These users are often characterized by excessive transmission frequency and power, alongside a lack of effective state management. They cannot actively respond to outbound beams and frame numbers. As a result, traditional positioning methods struggle to locate them accurately. To address the above challenge, this paper proposes a positioning method for BeiDou RDSS non-cooperative users. The method integrates a spatiotemporal grid with deep learning. First, a multi-epoch spatiotemporal grid feature sequence is constructed through discretization. This transforms the non-convex positioning problem into a classification–regression problem on a discrete grid. Second, based on multi-epoch raw observation features, a physically derived feature set is further constructed. It includes pseudorange differences, the rate of change of time differences, and the mean of multiple inbound time differences. This set enhances the model’s ability to perceive satellite geometry and the spatial–temporal characteristics of signals. Finally, a deep residual network architecture is designed. It mines the nonlinear mapping between observations and geographic locations, thereby achieving high-precision positioning. Simulation experiments are conducted using real ephemeris data and user samples covering the entire territory of China. Simulation results demonstrate that the proposed method substantially reduces positioning errors compared to conventional approaches, providing a new technical pathway for high-precision localization of large-scale non-cooperative targets .

Key words: BeiDou radio determination satellite service, non-cooperative user localization, deep residual network, spatiotemporal grid, time difference of arrival