卫星导航系统广域差分技术体系研究

High-precision wide area differential technology is the key and difficult point of Global Navigation Satellite System (GNSS) research. This project based on the user requirements and our own GNSS building needs researches the high-precision wide area differential technology of GNSS and proposes a high-precision wide area differential technology system suitable of China. This technology system will give the design theory and algorithm model of the GNSS high-precision wide area differential technology. The study results will provide support for our GNSS construction and development. The main research topics include:(1)the research of high-precision wide area differential positioning technology including real-time high-precision orbit determing technology based on carrier phase, navigation satellite clock error real-time computing technology, Ionospheric grid model fusing and refined processing technology and user precise point positioning technology. (2)the optimal design of system differential correction including satellite orbit correction optimization, satellite clock correction optimization and ionospheric grid correction optimization.(3)the research of the system differential correction broadcasting strategy including broadcasting channel and link design research, information broadcasting strategy research based on satellite and ground network.(4)the research of multi GNSS system integration wide area differential technology including high-precision wide area differential technology based on muti-constellation and muti-system.

高精度广域差分技术是全球卫星导航系统（GNSS）研究的重点和难点问题。本项目基于高精度用户需求及我国GNSS建设需求，开展GNSS高精度广域差分技术研究，提出一套适合我国特色的高精度广域差分技术体系，该体系将给出GNSS高精度差分设计的理论与算法模型，为我国GNSS后续建设与发展提供支撑。项目的主要研究内容包括：（1）高精度广域差分定位技术研究，主要开展基于载波相位的实时高精度定轨技术、导航卫星钟差实时测定技术、电离层格网模型融合与精化处理技术以及用户端精密单点定位技术研究。（2）系统差分改正数优化设计，主要开展系统轨道与钟差改正数、电离层格网改正数等优化设计。（3）系统差分改正数播发策略研究，开展发播途径选择与链路设计、基于卫星以及地面网的信息播发策略等研究。（4）多GNSS系统集成广域差分技术研究，主要开展基于多星座、 多源系统进行高精度广域差分设计的关键技术攻关。

本项目基于高精度用户需求及我国卫星导航建设需求，开展卫星导航高精度广域差分技术研究，提出了一套适合我国特色的高精度广域差分技术体系。该体系提出基于滑动窗口的短弧段精密实时定轨方法，给出了采用短时钟差预报算法的实时钟差估计算法，对比分析了不同模型对电离层网格校正的影响，完善了用户单点精密算法。针对未来四大核心星座的兼容应用场景，给出了多星座联合监测带来的多模数据的异步异构观测问题的工程解决方案，实现了多星座融合定轨，达到了厘米级的精确实时轨道测定。项目开展了播发参数和策略的优化设计，提出了广域差分与广域增强系统信息一体化兼容播发策略。. 项目执行三年来，共发表/录用 SCI/EI 检索期刊文章 7 篇，培养毕业硕士研究生5名。本项目的研究成果已在中国卫星导航重大工程建设中获得应用，项目研究成果有效支持了我国卫星导航系统建设和国际化工作。