GNSS实时卫星钟差估计技术进展

不依赖实体基准站增强信息的GNSS实时精密单点定位服务将逐渐成为主流定位模式。实时卫星钟差产品作为实时精密单点定位的关键先决条件之一,其精度直接决定实时精密定位服务的性能。计算实时卫星钟差的GNSS实时卫星钟差估计技术成为实时精密定位的核心技术之一,其主要包括两种解算模式:非差解算模式和差分解算模式。由于对卫星模糊度等未知参数处理策略的不同,卫星钟差估计技术又可细分为非差、历元差分、星间差分、混合差分等策略类型。针对不同实时卫星钟差估计技术的原理方法、算法效率、适用性等问题,综合目前已有相关研究成果的基础上,对GNSS实时卫星钟差估计的研究现状、关键技术和面临的挑战进行了较为系统的总结综述,并对未来卫星钟差预报产品和实时估计产品的关系进行了展望。

Technical Progress of GNSS Real-time Satellite Clock Offset Estimation

GNSS real-time precise point positioning services that aren''t dependent on enhanced information from reference station will gradually become the mainstream positioning mode. As one of the key prerequisites for real-time precise point positioning, real-time satellite clock offset products'' accuracy directly determines the performance of real-time precise positioning services. GNSS real-time satellite clock offset estimation technology, which calculates real-time satellite clock offset, has become one of the core technologies for real-time precision positioning. There are mainly two solution modes: un-differenced mode and differential mode. Due to the different processing strategies for unknown parameters such as satellite ambiguity, the satellite clock offset estimation technology can be subdivided into un-differenced, epoch-differenced, inter-satellite differenced, mixed-differenced and other strategy types. Aiming at the principle methods, algorithm efficiency, applicability and other issues of different real-time satellite clock estimation technologies, this paper systematically summarizes the current research status, key technologies and challenges of GNSS real-time satellite clock estimation based on existing related research results and gives the outlook of the relationship between forecasted satellite clock offset products and real-time estimated products.