The Analysis Of Integrity Indicators On Navigation Satellite System With Algorithm Research

With the rapid development of navigation system, it plays a more and more important role in military and civil field. Integrity is the capability of sending the alarm to the users timely when the navigation system is out of use and it is a significant parameter of satellite navigation system. For some safety-first applications, the integrity of the navigation system is the performance requirement that users concern most. So the research of the integrity is beneficial much to the construction and the evaluation of satellite navigation system.Based on the perspective of system analysis and optimization, this paper investigates the integrity concept, indicators and feedback from the system-level features and user-lever autonomous integrity. At the same time, the thesis uses COMPASS navigation system as the background of integrity simulation, studies RAIM algorithm dealing with multiple faults, the index analysis of the integrity equation, the layout of monitoring stations network and the integrity implementation strategy of the multiple navigation system. Specific research content and related innovations are as follows:(1)The receiver autonomous integrity algorithm is investigated, including the single fault RAIM algorithm and the double faults RAIM algorithm. Accordingly, an improved RAIM algorithm dealing with multiple faults is proposed based on the Maximum Likelihood Estimation and BIC criterion and the algorithm can judge the number and the location of the satellite failure.(2)The error sources of the COMPASS navigation system integrity calculation and the fault tree model are researched, the corresponding integrity equation is formed and the integrity index is analyzed combining with characteristics of COMPASS heterogeneous constellation. Considering the calculation of integrity indicators, an improved worst user location (WUL) algorithm is proposed. The theoretical analysis and simulation results show that the computational efficiency and accuracy of the new WUL algorithm have been improved than the original algorithm.(3)Based on the integrity equation, the layout of monitoring stations network of the COMPASS navigation system is analyzed. The differences and similarities between the network layout from the integrity and the layout from the perspective of traditional PDOP are analyzed.(4)Against multiple navigation system, Combining with different system-level features of GPS, Galileo, COMPASS satellite navigation system, etc, the system-level integrity collaboration based on integrity equation is studied and compared with the system-level integrity collaboration based on the integrity concept of GPS and SBAS system. At the same time the two implementation strategies are compared with simulation and analyzed with results.The conclusion of the research could provide a theoretical analysis and technical support for the construction and application of satellite navigation system .