基于星间链路的北斗定轨若干模型建立与精化研究

星间链路是北斗/GNSS的重要组成和发展趋势之一，目前在轨运行的19颗BDS-3卫星均实现了星间测距。基于星间链路的北斗高精度定轨中仍存在如下瓶颈问题：定轨残差含有幅值达15cm的残余系统误差；相对于星地L波段定轨，卫星偏航姿态和天线相位中心模型对星间链路定轨精度的影响过程和量级不同；不同卫星对构成的链路测距精度差异可达4-5倍。因此，本课题研究基于星间链路的北斗定轨函数模型和随机模型的建立与精化方法，利用长期实测的星间链路观测数据，在全面分析星间观测精度和误差特性的基础上，突破星间链路定轨残余系统误差修正方法、顾及观测值误差测量特性和赫尔默特方差分量估计的星间链路随机模型建立、卫星高精度相控阵天线相位中心和偏航姿态建模等关键技术，最终形成优化的北斗星间链路定轨理论方法和模型，并开发相应软件系统。研究成果可提高卫星轨道精度，丰富星间链路理论体系和拓展其应用。

The inter-satellite link (ISL) is one of the important components and development trends of BDS/GNSS. At present, 19 BDS-3 in-orbit satellites are equipped with high-precision ISL payloads. However, the following problems are needed to be settled in BDS high-precision orbit determination based on ISL. The orbital residuals contain systematic errors with amplitude up to 15 cm; the impact and magnitude of satellites yaw attitude model and antenna phase model on the accuracy of orbit determination using ISL are different, compared to orbit determination with L-band observations; the difference in ISL ranging accuracy of different satellite pairs can reach 4-5 times. Therefore, this project is to study the method of establishment and refinement for function model and stochastic model for BDS-3 ISL orbit determination. Based on long-term BDS-3 ISL observation data and a comprehensive analysis of inter-satellite observation accuracy and error characteristics, some key problems should be solved, such as model of inter-satellite orbit residual system errors, establishment of ISL stochastic model considering ISL observation error characteristics and Helmert variance component estimation, high-precision satellite phase array antenna phase center correction and yaw attitude modeling. Finally, this project will form an optimized BDS-3 ISL orbit determination theories and methods, and develop the corresponding software system. Moreover, the research results will improve the orbit accuracy, enrich the theoretical system of BDS-3 ISL and expand its application.