Research Of High-robustness Frequency Standard Taming Technology

With the progress of science and technology,high reliability and high precision frequency standard is very important in the fields of satellite navigation,measurement and test,control and communication,telecommunication and electric power,finance and so on.The time-frequency unified system of BD3 main control station in China is under construction.Its main function is to provide the ground control system of BD3main control station with high robust and high precision time-frequency signal.The technical research involved in the time-frequency unified system is summarized.Frequency standard taming is the common support technology of all kinds of equipment in the main control station.Based on the construction of time-frequency unified system of BD3 main control station,the taming technology of high-robustness frequency standard is studied in this thesis,and the project implementation scheme and test results are given.The research work has been carried out in the following aspects:1)According to the aging and temperature drift of different frequency standards,the main technical indexes of frequency standards are briefly introduced,the aging and temperature characteristics of different frequency standards are analyzed,and the mathematical model of frequency standards is established in this thesis.On the other hand,for the GNSS one-way timing,GNSS common-view comparison,and remote optical fiber time-frequency transmission,the three different application scenarios have different observation errors.The basic principles of the three application scenarios are introduced,and in different application scenarios,the error of the observed data was tested and analyzed,which laid the foundation for the taming of the frequency standard.2)Aiming at the error jitter of observation data in three different scenarios,the performance and characteristics of the commonly used loop filtering algorithm are compared.According to the comparison conclusion,the Kalman loop filtering algorithm is selected.The simulation results show that the clock errors in three scenarios converge obviously by adjusting the parameters of Kalman filtering in different scenarios.Aiming at the control of frequency standard taming,a method of taming based on PID position control is proposed and the measured data is simulated and analyzed.The simulation results show that the long-term stability and accuracy of the system can be effectively improved by adjusting the frequency standard with real-time PID control,and there is no large drift with the frequency standard.In order to improve the reliability and robustness of the system,a frequency standard time-keeping technique is proposed to ensure the output frequency accuracy in tolerable range after the observation is invalid.3)The engineering implementation and verification of high robust frequency standard taming technology is given.The test results of GNSS timing receiver of engineering prototype show that the frequency accuracy index increases from 10-10 to10^-12 relative to the original crystal oscillator index,and the time-keeping accuracy reaches±1.5 us?24 hours?which improves the reliability and robustness of frequency source.Test results of fiber optic transmission terminal index for engineering prototype show that the frequency accuracy index is increased from 10^-10 to 5*10^-13 and the long-term stability index is tamed to 10^-15.Finally,the taming technology of high-robustness frequency standard is summarized.This research has certain application value to the construction of high-robustness time-frequency reference signal.At the same time,it provides a realization scheme for the engineering application of high-robustness frequency standard taming technology.