BDS/GPS Multipath Error Modeling And Its Application In High Precision Deformation Monitoring

With the continuous development of China's economic construction and urbanization,large quantities of construction,such as large projects,infrastructure and residential buildings have been built throughout the country,and their upgrading and maintenance need the support and guarantee of high precision deformation monitoring.All weather,automation,and continuous high-precision deformation monitoring system become the key to solve such problems.As the GNSS satellite positioning technology itself has the advantages of easy automation and simple construction,the high precision deformation monitoring of GNSS,represented by GPS/BDS,is becoming a hot issue focused by researchers,government departments and related companies at home and abroad.In addition,with the continuous development of the Beidou navigation and positioning system(BDS)in China,it has been able to provide high precision navigation,positioning and time service services.It has shown great potential and advantages both economically and technically,providing a basis for the high precision deformation monitoring of GNSS.Most of the deformation monitoring projects are short baseline,high precision and real-time.So,the main contents of this paper are as follows:(1)The main errors and their influences in the GNSS deformation monitoring,represented by BDS/GPS,are studied.The influence of these errors on the short baseline positioning and the method of weakening are discussed.According to the basic principle of relative positioning,the multi-path error modeling method in the relative positioning of GNSS short baseline is summarized.(2)The multipath effect in the GNSS deformation monitoring is deeply analyzed,the generation mechanism and the influencing factors of the multipath generation are expounded,and the amplitude of the influence of the coordinate sequence of the station is discussed.(3)In view of the causes and characteristics of multipath errors,the main methods of multipath error reduction and modeling are compared and analyzed.The methods of coordinate range time series,observation range time series,observation range space correlation and carrier noise ratio are deeply discussed.The advantages and disadvantages of each method and the scope of application are verified by the measured data.(4)Based on the above multi-path modeling,this algorithm implements and develops a Beidou/GPS high precision deformation monitoring software.Combined with the actual needs of the project,this paper briefly introduces the structure of the software,analyzes and discusses the technical selection and difficult problems in the process of software development,and puts forward the selection basis and solution.(5)Using the data of a month,the data processing,real-time processing and real-time elimination of multipath error processing are carried out,and the results of the three are compared and analyzed.Experiments show that it is feasible to eliminate multipath effect in real time.