GNSS Integrity Monitoring Method,Technology And Application

Based on the existing navigation system, GNSS is a general designation of GPS, GLONASS, GALILEO and the COMPASS. With the technology upgrading of GPS and the comprehensively launches of GLONASS/GALILEO, the positioning precision was greatly improved, but navigation system integrity doesn't achieve the demand of syetem and user. Thinking of the user safety,the integrity of the navigation system is more important than the precision.However, at present, although GNSS system has become gradually perfect and the integrity monitoring of GNSS has been proposed, integrity monitoring of GNSS is still at a initial stage. System construction, algorithm research and standard specification of integrity monitoring are not developed into unified mode. In this paper, in order to solve a series of GNSS integrity monitoring theory, method, key technology, and the core algorithm, the theory, algorithm and key technologies of integrity monitoring were deeply studied,theoretical system of integrity monitoring was proposed,integrity monitoring algorithm and model was founded, and was applied in data processing of GPS/GALILEO system.Based on the character of GNSS, emission error, transmission error and reception error of signal were studied mainly from the view of signal error source. Through signal observation data and error analysis, to achieve different types of integrity monitoring, the grading system of integrity monitoring was established. The grading system of GNSS integrity monitoring by the space segment to the ground segment is divided into three levels:system level, monitoring station level and user level.On the system level of GNSS integrity monitoring, orbit error and clock error were mainly studied. Using IGS Precise ephemeris, satellite orbit integrity monitoring was implement based on satellite orbit integral theory and time series analysis theory. Using Hebei CORS network,satellite clock error was estimated,based on bias and precision of satellite clock error, satellite clock integrity monitoring was studied to detection gross error. Index parameters of integrity monitoring were analyzed.Under the GALILEO integrity monitoring idea, the concept and mathematical model of several important index parameters including SISE, SIS A, SISMA and WUL were proposed and worked out the corresponding software. Using Chinese and world GSS, GPS data and simulated GALILEO data, the data peorceesing and analysing of SISE,SISA and SISMA were accomplished.On the monitoring station level of GNSS integrity monitoring,this level of GNSS integrity monitoring is divided into two levels, the first is that refers to the monitoring station within the augmentation system, monitor differential information availability real time, judge the reliability of the differential information; another level is judge the monitoring stations itself availability within the system, identificate the station's own reliability. Before monitoring station level of GNSS integrity monitoring,SNR of L2C was achieved. Using network RTK mode of Hebei CORS as the augmentation measure, the integrity monitoring of difference information was realized based on monitoring station, the estimation of signal quality and the detection of fault satellite were actualized, AL and TTA paratemer were confirmed. The theory and algorithm of monitoring station autonomous integrity monitoring was studied, this theory was used to detect the fault monitoring station by using Hebei CORS network.On the user level of GNSS integrity monitoring, using the data of Hebei CORS, XPL was calculated. Based on multivariate statistical inference theory and vector similarity index, the new theory of similarity vector distance RAIM was studied, and another new theory of cluster analysis RAIM was studied. Using Hebei CORS network data, own kinematic data, and simulated GALILEO data, based on GPS single position, GPS network RTK position, GPS PPP position and GPS/GALILEO PPP position, the two new RAIM theory were used to detect multiple fault satellites.