Study On The GPS Data Processing Based On C/S Model

The traditional measurement for GPS static surveying is collecting data in previous,then using the post-processed model to resolve GPS data.Considering this way to obtain the result of data processing don't have the feature of immediacy,so in terms of timeliness it has a certain lag problem when applied in deformation monitoring or some urgent projects and so on.Secondly,the data is not visible during the observation process,so the quality of the data obtained by the receiver is unknowable.If the observation data is of poor quality,the solution result is often unacceptable.Therefore,we must re-observe,resulting in a great waste of manpower and material resources,seriously affecting the efficiency of work.Third,the use of professional software for data processing requires certain professional knowledge.Therefore,it has a great significance for routine field work if the results can be easily and quickly obtained.Consequently,this paper adopts a GPS data processing method based on C/S mode.That is,the client transmits the GPS data to the server for solving,and then the solved result is immediately transmitted back to the client.The research aspects and achievement include the following:(1)Due to the use of client/server interaction mode,in order to achieve data communication,the basic principles of computer networks and various types of communication protocols have been studied.(2)Researched the RINEX format file,compared the connections and differences between several different versions,realized the analysis of the format file,and laid the foundation for the following single-point positioning,baseline solving and other steps.(3)A detailed study of several commonly used cycle-jump algorithms was carried out.Phase-to-pseudorange and ionospheric residual algorithms were combined to detect cycle slips.Achieved excellent results were obtained by example tests.(4)In-depth study of the principle of single-point positioning,and detailed analysis of the positioning accuracy and DOP values through measured data,study the establishment and linearization of double-difference observation equations,achieved the floating solution of the baseline through the measured data.(5)After obtaining the floating solution,the ambiguities were fixed using the LAMBDA algorithm,and the floating solution and the fixed solution of the ambiguities are compared through calculation examples.At the same time,analyzing the accuracy of the fixed baseline vector in detail.(6)Since the conventional least squares method does not have robustness,a more secure adjustment method,i.e.,robust estimation,is used to perform GPS network adjustment,and studied its theory deeply.Through examples,it is shown that adjustments using robust estimation can obtain better estimates in the presence of gross errors.(7)This paper uses the Android platform for client application development.The platform uses a programming language of Java,and studied the Android development environment and developed a client application which is mainly used for sending and receiving data.