Algorithm Research Of Integrity Monitoring On Bdsbas Airborne

The Space Based Augmentation System(SBAS)can significantly enhance the accuracy,integrity and other navigation service performance,the differential and integrity information will converge on the airborne eventually,and the enhancement of integrity is the key problem to be solved in reality.This thesis centre on the airborne integrity monitoring algorithm of the BDSBAS.The main research work and results are as follows.1.The thesis specifies the basic structure,basic principle,data processing and system characteristics of the BDSBAS,puts forward the necessity of our independent development construction of BDSBAS and points out the advantages of BDSBAS.2.The thesis elaborates on the major error sources in the BDSBAS and analyzes each error model algorithm.Focuses on the study of the correction of the ionospheric delay error and further optimize the calculation method of the ionospheric grid point delay value.By the navigation and the observational data the thesis proves that grid ionospheric model can effectively weaken the effect of the ionospheric delay,and selects the ionospheric pierce point delay value which in the 1010??? intervals of the latitude and longitude in grid model to calculates the delay value of ionospheric grid point is more accurate.3.This thesis introduces the integrity enhancement techniques of the BDSBAS,the key research and simulated analysis three integrity parameters' algorithm,such as UDRE,RURA and GIVE.The simulation results show that the error values of UDRE,RURA and GIVE satisfy the application of the airborne terminal to the near-end of the terminal,and the GIVE values of the lattice sites have not reached the ideal value,the main reason is that the number of the selected national monitoring stations is small and the distribution range does not reach the good coverage performance,so that the delay calculation amount of the grid mesh ionosphere is not accurate enough.4.The thesis elaborates on the logical processing method of the airborne integrity monitoring technique of BDSBAS,focus study on the calculation method of the domain locate determine methods of the airborne users,simulates and analyzes the algorithm according to relevant data.The results certify that the BDSBAS provides the performance of navigation service has the ability to provide the APV-I flight phase to single-frequency users in the Chinese mainland,however,the system's protection level has not yet reached civil aviation requirements for the higher level of precision landing services such as APV-II,which do not yet provide a higher level of service.