Study On The Timing Performance Evaluation Of Beidou Satellite Navigation System

An important function of satellite navigation system is timing service. It is preconditionof timing to carry on the measurement and synchronocme of time information. This willrequire the clocks of each part of satellite navigation system, including the space part andground part and customer part, synchron to a unify standard dimension as a time basis. In themeantime, according to International Telecommunications Union, the deviation betweensystem time and standard time UTC should maintain at the100ns, therefore, satellitenavigation system have to deal the problem of its system tracing to origin firstly, then the highaccuracy time service.According to the development of time transfer methods and the satellite navigationsystem, this dissertation studies and researches the principles and algorithms of evaluationmethods for system time performance detailedly and systematically. Then, the performance oftiming service is carried out and analyzed. The contents and results of this paper are asfollows：(1) This dissertation studies the development of timing service of satellite navigationsystem. This paper also introduced the background and significance of research on theevaluation of navigation system time.(2) Kinds of the system time used in the navigation system and the methods of timingservice of BeiDou satellite navigation system are in detailed. In addition, the method oftiming and its basic principle are explained. Then, the types of errors source and its processingmethods, as well as the correction methods or solutions are discussed.(3) This dissertation mainly studies the theory of the evaluation of satellite navigationsystem time. The principles and algorithms of three methods, including GPS common view,BeiDou common view and two-way satellite time and frequency transfer, are brieflydiscussed. Based on BeiDou satellite navigation system, the time offset of BDT(BeiDouSystem Time) and UTC(NTSC) standard time are calculated after the data preprocessing andthe error correction. Then, we introduced the Kalman and Vondrak smooth methods in detail,and analyze their characteristics respectively.(4) According to the experiment analysis, the stability analysis, the comparison andanalysis are given depending on the experiment results, to some extent providing the relevantvalue for the relevant technical improvement and performance study and time service and so on. The results showed that the maximum of time offset is86ns, the frequency accuracy isunder3×10-14, the frequency drift rate is under4×10-14, while the frequency stability of BDTrelative to UTC(NTSC) is under5×10-14/day.(5) This dissertation presented the basic principles of timing service methods. Then, thekey techniques of timing service are discussed. Then, an experiment of static timing accuracyevaluation in state fixed is carried on, which aiming to validate timing function of the testterminal in the verification ground controls system. The test terminal should have functions ofreceiving, following the containment signal, processing, calculating etc. In the nature ofthings, the accuracy evaluation will be obtained. According to the results of the three test setsfixed on the customer’s machines, the standard deviation are36.55ns、37.53ns、35.27nsrespectively.