Research On The Method Of Performance Improvement Of Remote Time Frequency Traceability Based On GNSS Common View

With the increasing demand about time frequency standard in the society,it is important to discipline the source of the time frequency equipment remotely,considering that equipment calibration is time-consuming and laborious and the equipment in transit is possibly damaged.Thus NIMDO(A UTC(NIM)disciplined oscillator)is developed by NIM(National Institute of Metrology),and the equipment can realize real-time remote time frequency traceability.Considering the problem of data transmission and the poor stability in practical applications of NIMDO,the paper mainly studies the Beidou short message communication and the algorithm of disciplining atomic clock based on kalman filter.The main contents of this paper include:1.The application of Beidou Short message communication in remote time traceability system is proposed.The coding method adapted to the requirements of the Beidou short message and the data information of the receiver which contains the remote traceability is designed,and the software is applied to the real-time data transmission of the remote time traceability system successfully,and the experiment is designed to verify its effect.Beidou Short message communication can meet the needs of remote time frequency traceability.2.An algorithm of disciplining atomic clock based on kalman filter is proposed.The main contents include:the analysis of the main noise of different types of atomic clocks by using the frequency stability of atomic clocks;research the modified algorithm of disciplining atomic clocks and the performance of the current disciplining algorithm processing the noise.The paper design the modified algorithm of disciplining atomic clocks based on kalman filter.3.The paper conducts the filtering test with the CGGTTS(Common Generic GNSS Time Transfer Standard)data and the comprehensive test about the system of the disciplining the atomic clock.The simulation test is also carried out for special cases such as data gap and jumping.Based on the NIMDO system structure,the remote time frequency transfer platform is built,and the improved algorithm is validated experimentally.The results show that the improved algorithm can reduce the effect of atomic clock noise and improve the short-term stability of the disciplining effect,and also can guarantee the system running normally under special cases,and improve the stability of the operation of the system.