Optimal Design Of GPS Control Network And Study Of GPS Data Processing

With the development of global satellite positioning technology, GPS with itssignificant advantages gradually replace the traditional geodetic positioning methods,its appearance bring s innovative changes to mapping disciplines. As the technologyhas been increasingly widely used in a variety of engineering, how to improve theaccuracy of GPS control network has become one of the important tasks and issueswithin their field of study.This paper introduces the principle of GPS measurements, sources of error andits differential mathematical models, through the analysis and optimization design ofGPS control network, different results of observational data processing and datacontent coordinate system conversion, through engineering applications instance datacomparison, combined with the practical applications and related examples for study.Paper is organized as follows:1. Based on the observation of the principle of GPS technology, this paperelaborate the error sources and influence from observation process, including thesatellite component, the propagation path, the ground segment. And analysis thatwhich suitable methods should be used to be reduced or eliminated these errors. Inaddition, on the point of three kinds of differencing method principle, study its effecton solving processes and eliminate the errors;2. Discuss the theory of GPS control network optimization design, summarizesthe content of control network zero class, and class I, II, III’s design. Analysis GPSnetwork optimization design of precision, reliability, cost, sensitivity four assessmentindicators, summarized how to improve the accuracy and reliability of GPS ControlNetwork. Finally, introduced three types of GPS network optimization studies,through comparative observation programs and optimization of a city urbantransformation of the old network control network control network observationprograms, compared to the results of the two-year program of observational data andindicators parameters, can be drawn reasonable distribution network optimizationprogram can reduce the workload, increase efficiency and greater accuracy of thisconclusion; 3. Baseline solution and network adjustment are important steps of GPS ControlNetwork Observation data processing, paper takes GPS observation data processingfor the topic, analyzed three baseline solution modes, the results of baseline solutionquality control and evaluation, and baseline refinement methods. Studies the GPScontrol network unconstrained model and observation data error and constrainedleast squares adjustment equation. Choose a commonly used commercialpost-processing software, and take TBC as an example to analysis the process controlnetwork GPS observation data.4. Discussion on the four common coordinate systems we always used: theBeijing54coordinate system, the Xi’an80coordinate system, WGS-84coordinatesystem, the National2000coordinate system, and Gauss-Kruger projection andUniversal Transverse Mercator projection methods. Studies the principle of fourkinds of coordinate transformation models, and according to the distribution aroundthe country in a city of eight control points at Beijing54coordinate system and theresults of Xi’an80coordinate system, select a four-parameter model andseven-parameter model of existing control point coordinates conversion, bycomparing the two the method of conversion accuracy of the results, obtained in thecontrol points are distributed over a certain range, seven-parameter method toconvert the results to be better than four parameters.