Stability Analysis Of Regional CORS Station Based On BDS

With the completion of the global networking of Beidou satellite navigation system,more and more continuous operating reference stations in China have been transformed from single mode to multi-mode,which enables CORS stations to receive observation data of multiple satellite navigation systems at the same time.CORS station is the reference station for users of all walks of life in high-precision positioning,real-time positioning and navigation services.The stability of CORS station determines the reliability and accuracy of providing the reference.Therefore,the stability analysis of CORS station based on Beidou system is of great significance both in theory and practice.In this paper,the stability of regional CORS station based on Beidou is studied from the aspects of data quality,baseline accuracy,point accuracy,time series and stability by using the observation data accumulated by multi-mode CORS reference station.The specific research contents are as follows:1.Beidou data quality analysis.After analyzing the theory of Beidou high-precision data processing and the factors affecting the high-precision data processing of Beidou,the data quality of Beidou satellite sky map,signal-to-noise ratio,multi-path and other aspects are analyzed,and the observation data with poor quality are eliminated,which is helpful to improve the accuracy and reliability of Beidou high-precision data processing.2.Precision analysis of short baseline and medium-long baseline of Beidou.Taking the data of multi-mode reference station as an example,the accuracy of short baseline and medium-long baseline of Beidou and GPS are compared and analyzed.The results show that the horizontal direction of Beidou baseline is basically the same as that of GPS,and the vertical accuracy is slightly lower than that of GPS.3.Analysis of relative positioning accuracy under different systems.The precise relative positioning accuracy of single BDS,single GPS and BDS+GPS integrated system is analyzed by introducing multi-mode MGEX stations in and around China and multi-mode CORS reference stations in Beijing area for data processing.The results show that the precision relative positioning accuracy of single BDS is slightly lower than that of single GPS,while the precision relative positioning accuracy of BDS + GPS combined system is better than that of single system.4.Time series velocity field analysis.For the original coordinate time series,the gross errors are eliminated and the missing data are interpolated.Then the coordinate time series are linearly fitted by the classical least square method.Finally,the velocity fields of regional CORS stations under different systems are analyzed.The results show that single BDS,single GPS and BDS+GPS combination systems can monitor the velocity field of regional CORS stations,the accuracy of velocity field estimation of BDS+GPS combination system is higher.5.Stability analysis of regional CORS station based on Beidou.By introducing Pearson correlation analysis theory,Pearson correlation coefficient between regional CORS station change and IGS tracking station change under Beidou system is obtained.It shows that the migration trend of CORS station has a significant correlation with plate movement.Accordingto the location accuracy,the stability of regional CORS station studied in this paper is analyzed.