Research On Evaluation Methods Of GPS/BDS Satellite Navigation System Signal In Space Perfprmance

Since the GPS(Global Position System)was officially put into use in the last 1990 s,satellite navigation positioning technology and its applications have been developing at a rapid rate.Today,with the development of other navigation systems,the comprehensive performance of the system has gradually become the key factor in the competition.This thesis studies the Signal-In-Space(SIS)accuracy and integrity performance evaluation method of GPS/BeiDou,then the geometric method is used to study the worst user position in integrity.According to the actual data,the performance of Medium Earth Orbit(MEO)single star and the performance of navigation constellation are studied.Based on the single star performance model,the constellation system performance evaluation model is studied.The specific research work is as follows:Firstly,the accuracy and integrity evaluation indicators and the calculation method of satellite position both of GPS and Beidou are introduced.The precise ephemeris provided by IGS and the navigation ephemeris data received by the local receiver are used to evaluate the SIS accuracy and integrity performance of GPS and BeiDou.Modeling and analyzing the spatial signal accuracy of GPS and BeiDou using the segmentation evaluation model and Allan variance.The simulation of the integrity of GPS SIS URE is carried out.Then the geometric method is used to analyze the worst user position,which is the important parameter in the calculation of integrity.The traditional geometric method is improved by the coordinate rotation method.The simulation is analyzed based on the GPS navigation message obtained by the local receiver and the precise ephemeris provided by the IGS data center,which is used to verify the precision of the method.According to Availability?Dependability?Capability model,the Medium Earth Orbit single star and constellation performance evaluation model is established based on the Markov process.The model was simulated and analyzed based on the actual data.Finally,according to the calculation model of Signal-In-Space accuracy and integrity,the GPS/BeiDou SIS performance evaluation software is designed using matlab.Based on the actual data,the accuracy,integrity,and performance of the single star and constellation were evaluated for GPS and BeiDou.Then verifies the effectiveness of the evaluation model.The results of research in this thesis will have certain reference significance for the related research of satellite navigation performance evaluation.