基于月球掩星观测的星上全自主校时方法  

On-board Autonomous Time Calibration Method Based on Lunar Occultation Obsercations

作　　者：侯祥震 刘玥[1] 付凯林 钱霙婧[2] HOU Xiangzhen;LIU Yue;FU Kailin;QIAN Yingjing(DFH Satellite Co.,Ltd.,Beijing 100094,China;Beijing University of Technology,Beijing 100060,China)

机构地区：[1]航天东方红卫星有限公司,北京100094 [2]北京工业大学,北京100060

出　　处：《航天器工程》2024年第4期18-24,共7页Spacecraft Engineering

摘　　要：针对现有自主任务规划和自主导航任务对星上时钟准确性的依赖程度,以及当前卫星广泛依靠地面和全球导航系统(Global Navigation Satellite System, GNSS)等外部系统校时的现状,提出利用星上姿态敏感器测量月球掩星现象,根据星载高精度星表反演掩星精确时刻,进而校正星上时钟,为自主导航和自主任务规划提供高精度时间基准。首先推导了掩星时间序列以及对观测时刻偏差的最小二乘算法,提出基于遗传算法的校时修正量计算方法,其次对掩星事件的可探测性进行仿真分析,最后利用仿真对基于遗传算法的星上自主校时仿真系统的有效性进行验证,仿真结果显示该时钟校准方法有效且可行,偏差优于0.005 s,可作为微小卫星、深空探测等项目星上校时的备用手段。The autonomous planning and scheduling of the satellite is highly dependent on In response to the dependence of existing autonomous mission planning and navigation on the accuracy of the on-board clock,as well as the current situation where satellites widely needs to be calibrated by the external information such as Global Navigation Satellite System(GNSS)or ground time service system.This paper proposes a method to measure Lunar Occultation using on-board attitude sensor,retrieve the exact time of occultation according to the on-board high-precision star catalogue,and then correct the on-board clock to provide a high precision time reference for autonomous navigation and autonomous mission planning.Firstly,the time series of occultation events and the least square algorithm for the deviation of observation time are deduced,and the calculation method of time checking correction based on genetic algorithm is proposed.Secondly,the detectability of occultation events is simulated and analyzed.Finally,the effectiveness of the on-board autonomous time calibration simulation system based on genetic algorithm is verified by simulation.The simulation results show that the clock calibration method is effective and feasible,and the deviation is better than 0.005s,which can be used as a backup means for satellite calibration in projects such as micro-satellite and deep space exploration.

关 键 词：月球掩星 时间序列 最小二乘法 遗传算法 星上自主校时 

分 类 号：V448.2[航空宇航科学与技术—飞行器设计]