Research On BDS Timing Monitoring Algorithm And Software Implementation

The Beidou satellite navigation system is a satellite system independently established in China,and plays a pivotal role in the fields of navigation and positioning,short message communication and timing.With the establishment of the BDS-3,the service of the Beidou satellite navigation system will expand to the global region in the Asia-Pacific region.It is imperative to carry out China's independent "Beidou PNT".As an important part of the "PNT"system,timing is gradually being promoted and applied in many industries such as power industry,communication industry and transportation.Satellite timing has the advantages of high precision,wide range and all-weather,so it has great advantages and development prospects in timing.In particular,in recent years,China has developed rapidly in terms of national defense and space technology,and the corresponding stability requirements for time transmission are also getting higher and higher.To ensure the correctness and stability of the timing results,monitoring for timing is particularly important.Based on the existing timing monitoring methods and timing characteristics,this paper develops the BDS single-frequency timing monitoring algorithm research and application software development,and completes the theoretical research,program design,test analysis and software application development of single-frequency timing monitoring.A variety of timing monitoring methods have been introduced or proposed,and a complete timing system has been constructed to greatly improve the monitoring efficiency and ensure the correctness and stability of the timing results.The main research contents of this paper are as follows:(1)Starting from the BDS timing to be built and promoted,based on the principle of BDS single frequency timing,the principle,model,algorithm and process of the existing data quality monitoring method are summarized.According to the timing characteristics,the receiver clock jumps detection is introduced for the first time in data quality monitoring,which avoids the abnormality of the timing result caused by the receiver clock jumps.(2)In order to ensure data quality,two methods are designed according to the number of monitoring stations:when determining the number of stations in the epoch,the number of stations is abnormal.When there is no abnonnal number of stations in a certain epoch,the principle of obeying the majority is adopted;if the two are equal,the judgment is based on the single-frequency monitoring method based on RAIM.The problem of inconsistent monitoring results during multi-station monitoring is solved,and the correctness of data quality is ensured.(3)The existing threshold method for monitoring the timing results is studied.According to the relationship between the receiver clock error and the timing result,the receiver clock error prediction theory is analyzed.The timing comparison method based on quadratic polynomial is proposed to solve the timing.The result threshold method cannot detect the problem of abnormal timing results within the threshold.(4)The deficiencies of data quality monitoring and timing results monitoring are described,indicating the limitations of single data quality monitoring or timing results monitoring in timing.This paper designs and constructs a timing system that integrates data quality monitoring,timing monitoring,and timing results monitoring.Through experimental analysis,the monitoring efficiency under the timing system is significantly improved compared with the single data quality monitoring or timing monitoring.(5)Based on the timing system,the timing software was written to realize post-or real-time single-frequency timing monitoring and calculation.