基于Kalman滤波的导航星座集中式守时算法研究  

Research on centralized time-keeping algorithm for navigation constellations based on Kalman

作　　者：樊礼谦 焦文海[2] 孟轶男[2] FAN Li-qian;JIAO Wen-hai;MENG Yi-nan(Institute of Geospatial Information,Information Engineering University,Zhengzhou 450001,China;Beijing Institute of Tracking and Telecommunication Technology,Beijing 100094,China)

机构地区：[1]信息工程大学地理空间信息学院,郑州450001 [2]北京跟踪与通信技术研究所,北京100094

出　　处：《时间频率学报》2023年第1期21-31,共11页Journal of Time and Frequency

摘　　要：自主守时是指无地面段支持情形下,仅利用星间测距和通信维持卫星导航系统时间。首先介绍了基于卡尔曼(Kalman)滤波的集中式自主守时算法,然后采用哈达玛(Hadamard)方差估计了星载原子钟的噪声系数,最后利用IGS(International GNSS Service)精密钟差进行了自主守时仿真试验,评估了整体时间漂移、频率稳定度等自主守时性能。结果表明,集中式Kalman滤波自主守时算法可实现星座内时间基准统一,通过对预报性能较好的氢钟的噪声参数进行优化可以提升自主守时性能,自主运行60 d后时间漂移约11.4 ns,天稳定度优于5.0×10^(-15),优于任意单一主钟的预报漂移精度和频率稳定度。Autonomous time-keeping refers to the use of inter-satellite ranging and communication to maintain the satellite navigation system time without ground segment support.This contribution first introduces the centralized autonomous time-keeping algorithm based on Kalman filter,then estimates the noise parameters of the on-board atomic clock using Hadamard variance.Finally,the IGS precise clock biases are used for autonomous time-keeping simulation experiments to evaluate the overall time drift,frequency instability,and other autonomous time-keeping performance.The results show that the centralized Kalman filter autonomous time-keeping algorithm can realize unified time reference,and the autonomous time-keeping performance can be improved by optimizing the noise parameters of the hydrogen clocks with better forecast capability.The time drift after 60 days of autonomous operation is approximately 11.4 ns and the instability is less than 5.0×10^(-15)at 1 day intervals,which are better than the forecast drift accuracy and frequencyinstability of any single master clock.

关 键 词：集中式卡尔曼滤波 自主守时 哈达玛方差 星间链路 

分 类 号：V474.25[航空宇航科学与技术—飞行器设计] TN96[电子电信—信号与信息处理]