Advances and Challenges in Resilient Fusion Navigation Technology Based on Multisource PNT Information: A Review

Driven by the rapid evolution of the low-altitude economy and intelligent autonomous systems, users increasingly require higher standards of resilient positioning, navigation, and timing (PNT) service capabilities. We first analyze the core key technologies required for PNT systems to achieve resilient service capabilities, categorizing them into two main areas: technologies oriented toward PNT terminals/systems and user resilient services, and those oriented toward resilient PNT information processing. Second, we provide a comprehensive review of the research progress in key technologies, including the resilient integration of PNT terminals/systems and information, PNT functional and stochastic models, as well as multisource PNT information fusion and resilient services. Furthermore, we discuss the challenging issues that must be addressed to realize the resilient service capabilities of PNT systems, including the performance infimum of PNT systems in different user scenarios, component-based resilient integration of PNT sensors, application context-intelligent perception and functional model library construction, and the resilient framework and credible performance assessment technologies for PNT systems, in which the concept of relative autonomous integrity is introduced.