| 摘要: |
| 针对基于卫星共视的时频网络绝对零值标定方法复杂且成本高的问题，提出了一种利用多通道计数器的高精度且易操作的零值标定方法。首先将主节点全球卫星导航系统（Global Navigation Satellite System，GNSS）时频终端将生成的多路10 MHz频标分别送到从节点GNSS时频终端，实现主从频标共源。主从节点GNSS时频终端接收卫星导航信号，实现站址精确测量，并完成各节点GNSS时频终端与可视卫星钟差测量。从节点GNSS时频终端将钟差测量值送到主节点GNSS时频终端，根据接收到的导航信号信噪比自适应加权获取站间钟差，同时高精度多通道计数器实时接收主从节点输出的秒脉冲（1 Pulse per Second,1PPS）信号，测量各从节点与主节点的1PPS时间间隔。对主节点GNSS时频终端计算的站间钟差及多通道计数器测量的1PPS时间间隔进行约2 h的采集，基于两项数据完成时频网络站间零值标定。实测数据结果表明，所提出的零值标定方法可实现站间高精度时间同步，且同步精度优于6 ns，为基于卫星共视的站间高精度时频同步提供了技术支撑。 |
| 关键词: 卫星共视 时频同步网络 零值标定 时间同步 钟差 |
| DOI：10.20079/j.issn.1001-893x.20240620008 |
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| 基金项目: |
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| A Zero-value Calibration Method for High Precision Time-Frequency Synchronous Network |
| WANG Mingjuan,YANG Junwei,GUO Qingfeng |
| (1.Unit 91550 of PLA,Dalian 116023,China;2.Southwest China Institute of Electronic Technology,Chengdu 610036,China;3.Chengdu Spaceon Electronics Co.,Ltd.,Chengdu 610015,China) |
| Abstract: |
| For the complexity and high cost of the absolute zero-value calibration method for the time-frequency networks based on satellite common-view,a high precision zero-value calibration method using multi-channel counters is proposed,which is easy to operate.The Global Navigation Satellite System(GNSS) time-frequency terminal of the master node sends multi-channel 10 MHz frequency markers to the GNSS time-frequency terminal of the slave node to achieve co-sourcing of master-slave frequency markers.The primary and secondary nodes’ GNSS time-frequency terminals receive satellite navigation signals for accurate site measurement and complete clock difference measurement between their visual satellites and each node’s GNSS time-frequency terminal.The slave node’s GNSS time-frequency terminal sends its clock difference measurement value to that of the master node.The inter-station clock difference is obtained according to adaptive weighting based on signal-to-noise ratio from received navigation signals.Simultaneously,in real-time,a high-precision multi-channel counter receives 1 pulse per second(1PPS) signals from both master and slave nodes and measures their respective intervals with respect to each other.The inter-station clock difference calculated by the master node搒 GNSS time-frequency terminal and measured 1PPS intervals are collected for about 1 hour,and their mean value represents zero-value between primary and secondary nodes.Experimental data shows that the proposed zero-value calibration method can achieve an inter-station synchronization precision less than 6 nanoseconds,providing technical support for high precision time-frequency synchronization between stations based on satellite common-view. |
| Key words: satellite common-view time-frequency synchronous network zero-value calibration time synchronization clock difference |
