基于GNSS的列车时频溯源与同步方法及性能评估OA

To address the issues of inconsistent traceability for train time nodes and the isolation between train-to-ground and train-to-train time-frequency within the current railway time synchronization network,a method based on Global Navigation Satellite System(GNSS)for train time-frequency traceability and synchronization was proposed.By constructing high-precision time-frequency transfer and traceable synchronization links between train-to-ground and train-to-train nodes,the time-frequency transfer and traceable synchronization between train and ground nodes and among train nodes were realized.A dedicated device was developed,and the integrated performance of time-frequency transfer and traceability of the train was first evaluated based on the round testing railway line of the National Railway Testing Center.The results demonstrate that the noise level of time-frequency transfer link between train-to-ground is 2-6 ns,with an uncertainty of 6.6 ns.The noise level of time-frequency transfer link between train-to-train is 4-7 ns,with an uncertainty of 7.5 ns.In over 90％of cases,the train node can achieve high-precision reproduction for the time scale of the ground node with a difference of less than±10 ns.This method can provide reference and support for high-precision time-frequency transfer and traceable synchronization between train-to-ground and train-to-train nodes.