Shangguan Yong, Zhang Hua, Yu Yong, Wang Wenjin, Liu Bin, Li Haihan, Ma Rong
School of Information Science and Engineering, Southeast University, Nanjing 210096, China.
Beijing Research Institute of Telemetry, China Aerospace Science and Technology Corporation, Beijing 100076, China.
Sensors (Basel). 2025 Apr 18;25(8):2566. doi: 10.3390/s25082566.
Traditional spacecraft orbit determination primarily employs two methodologies: ground station/survey ship-based orbit determination and global navigation satellite system (GNSS)-based orbit determination. The ground tracking measurement system, reliant on multiple tracking stations or ships, presents a less favorable efficiency-to-cost ratio. For high-orbit satellites, GNSS orbit determination is hindered by a limited number of receivable satellites, weak signal strength and suboptimal geometric configurations, thereby failing to meet the demands for the continuous, high-precision orbit measurement of overseas high-orbit satellites. Satellite navigation systems, characterized by global coverage and Ka-band inter-satellite links, offer measurement and communication services to extended users, such as satellites, aircraft, space stations and other spacecraft. With the widespread adoption of navigation satellite systems, particularly in scenarios where ground tracking, telemetry and command (TT&C) stations are out of sight, there is a growing demand among users for Ka-band inter-satellite links for high-precision ranging and orbit determination. This paper introduces an innovative unidirectional orbit-determination technology for extended users, leveraging the navigation Ka-band inter-satellite link. When extended users are constrained by weight and power consumption limitations, preventing the incorporation of high-precision atomic clocks, they utilize their extensive capture capability to conduct distance measurements between navigation satellites. This process involves constructing clock error models, calculating clock error parameters and compensating for these errors, thereby achieving high-precision time-frequency synchronization and bidirectional communication. The technology has enhanced the time and frequency accuracies by three and two orders of magnitude, respectively. Following the establishment of bidirectional communication, unidirectional ranging values are collected daily for one hour. Utilizing these bidirectional ranging values, a mechanical model and state-transfer matrix are established, resulting in orbit-determination calculations with an accuracy of less than 100 m. This approach addresses the challenge of high-precision time-frequency synchronization and orbit determination for users without atomic clocks, utilizing minimal inter-satellite link time slot resources. For the first time in China, extended users can access the navigation inter-satellite link with a minimal allocation of time slot resources, achieving orbit determination at the 100 m level. This advancement significantly enhances the robustness of extended users and provides substantial technical support for various extended users to employ the Ka inter-satellite link for emergency communication and orbit determination.
基于地面站/测量船的轨道确定和基于全球导航卫星系统（GNSS）的轨道确定。依赖多个跟踪站或测量船的地面跟踪测量系统，其效率成本比不太理想。对于高轨道卫星，GNSS轨道确定受到可接收卫星数量有限、信号强度弱和几何构型不理想的阻碍，从而无法满足对海外高轨道卫星进行连续、高精度轨道测量的需求。以全球覆盖和Ka波段星间链路为特征的卫星导航系统，为卫星、飞机、空间站和其他航天器等扩展用户提供测量和通信服务。随着导航卫星系统的广泛应用，特别是在地面跟踪、遥测和指令（TT&C）站视线不可及的场景中，用户对用于高精度测距和轨道确定的Ka波段星间链路的需求日益增长。本文介绍了一种利用导航Ka波段星间链路的面向扩展用户的创新单向轨道确定技术。当扩展用户受到重量和功耗限制，无法搭载高精度原子钟时，他们利用其广泛的捕获能力在导航卫星之间进行距离测量。这个过程包括构建时钟误差模型、计算时钟误差参数并对这些误差进行补偿，从而实现高精度的时间频率同步和双向通信。该技术分别将时间和频率精度提高了三个和两个数量级。在建立双向通信后，每天收集一小时的单向测距值。利用这些双向测距值，建立力学模型和状态转移矩阵，从而进行精度小于100米的轨道确定计算。这种方法利用最少的星间链路时隙资源，解决了无原子钟用户的高精度时间频率同步和轨道确定难题。在中国首次实现了扩展用户以最少的时隙资源分配接入导航星间链路，实现了百米级的轨道确定。这一进展显著增强了扩展用户的鲁棒性，并为各类扩展用户利用Ka星间链路进行应急通信和轨道确定提供了有力的技术支持。
