Technology And Research Of Two-Way Time Frequency With High Accuracy

In order to build a unified time and frequency in the distant between the two systems,this would require the application to the distance of time and frequency transfer and technical means.In recent years,With the wide application of radio technology,In satellite navigation,radar,electronic reconnaissance,measurement and control and other fields,accuracy requirement in time is becoming more and more high.The high precision time and frequency synchronization method,mainly with GPS satellite and two-way satellite time frequency method two kinds.Depending on the time and frequency synchronization method with the help of a satellite navigation system,but the navigation signal is easily influenced by outside distractions,so limited precision and real-time performance also is poorer;The main method for time frequency two-way transfer is using special equipment,satcom communication with each other by the synchronous satellite transparent transponder implementation,high accuracy,good real-time performance,has a certain anti-interference ability.So it has been adopted by ITU(international telecommunication union)as global time transfer standard.With the maturity of GPS technology used,people often use the GPS satellite visual method to realize the remote time unification,but GPS method is difficult to achieve total nanosecond precision of timing.In order to improve the timing precision,two-way satellite time frequency method in recent years gradually into people's horizons,and widely used in measurement and control systems,radar,navigation systems,and other fields.How to improve the two-way satellite time and frequency comparison method of timing accuracy and anti-interference ability has become the important topic for the researchers discussed.This paper first introduces the concept of two-way time and frequency ratio on technology,then its working principle were expounded,and its working process was introduced in detail,illustrates the system structure and system design.Then further analyzes the two-way time and frequency ratio on composition and working principle of the equipment,function description of composition module in detail,and the key technologies involved in this paper.Finally,the IF index test and the RF index test were carried out by using two sets of satellites.The result can be obtained from the test result,the IF precision can be less than 3ns,and the accuracy of RF is less than 10 ns.Compared with GPS satellite,the advantages of two-way time frequency comparison technology are obvious and the application prospect is very broad.