一种基于异源状态的星间链路零值标定方法

A method of delay calibration on inter-satellite-link based on different reference

星间链路分系统零值标定的准确性,直接影响系统在轨星间双向测距和星座高精度时间同步准确度。地面标定通常采用的同源状态需要地面多路输出高稳10 MHz铷钟源支持,且标定状态与系统在轨应用状态并不完全一致。针对同源标定的局限性,提出一种异源状态星间零值标定方法,构建理论模型并进行了误差分析,异源零值标定的准确度受星座两星参考源(铷钟)的钟漂移特性、卫星遥测下传的时效性以及两星1 PPS状态一致性等因素共同作用。经系统实测验证表明:异源状态下星间零值标定误差约为1.901 ns,能够满足系统标定的精度要求。异源标定简化测试系统,与在轨应用状态高度一致,对工程实践具有一定参考和应用价值。

The accuracy of delay calibration of inter-satellite link subsystem directly affects dual ranging and high-precision time synchronization of system in-orbit,the common reference state is usually adopted at ground calibration,which requires the support of multichannel output of high stability 10 MHz rubidium referecne,but the calibration state is not completely consistent with the in-orbit application state of system.Aiming at the limitation of common reference,different reference state of delay calibration method is proposed and a detailed error analysis is carried out,it shows the error affected by the reference drift characteristic of the two satellite reference sources,the timeliness of satellite telemetry and the consistency of the state on two satellite 1 PPS.The delay calibration error is about 1.901 ns by different reference state,which can meet the requirements of system.In engineering practice,the different refferenc state of delay calibration has certain reference and application value.