Technology Research Of Integrity Monitoring On Sbas Airborne

In order to enhance China's international competitiveness in the field of navigation and positioning,to avoid the monopoly situation of satellite navigation systems in individual countries and to improve the reliability of global navigation and positioning,China has independently developed the Beidou Satellite Navigation System(BDS).As the auxiliary augmentation system of Beidou satellite navigation system,the satellite-based augmentation system(SBAS)has obvious improvement effects on the accuracy and integrity of the system,so it is widely used in the civil aviation field.Based on the Beidou satellite navigation system,a series of theoretical knowledge and algorithm simulation analysis of the airborne end integrity monitoring technology of the satellite-based augmentation system are carried out.The main research work and achievements are as follows:1.The whole structure of the satellite-based augmentation system is introduced.The functions of the three parts of the space part,the ground part and the user part of the system are explained in detail.The working principle and characteristics of the Beidou satellite-based augmentation system are expounded.2.The basic concepts of the parameters related to the airborne end integrity monitoring of the satellite-based augmentation system and the integrity index of the Beidou system are summarized.The basic principles of the satellite-based augmentation system integrity monitoring under the fault satellite hypothesis are introduced,and the civil aviation is analyzed.Navigation performance requirements for the flight approach phase.3.The main errors of the Beidou satellite-based augmentation system in the signal propagation process are discussed.The models and algorithms of each error correction are described in detail.For the ionospheric delay error with the greatest influence on the signal,the grid model is used to correct the ionospheric delay.The algorithm uses a series of improvements for the interpolation method used to solve the penetration point delay value of the grid point delay value in the grid model.The vertical point delay value of the penetration point is calculated by the linear interpolation method.The correction effect is closer to the true delay value.4.The related algorithms for the monitoring of the airborne end of the satellite-based augmentation system are studied.the calculation methods of the three integrity parameters of UDRE,RURA and GIVE of the star-based augmentation system are also specified.The performance of the multi-constellation SBAS is analyzed.According to the requirements of the Beidou satellite navigation system service standard,the SBAS integrity monitoring of different constellations under the faulty satellite hypothesis is monitored.Impact to explore and simulate.The MMS-based airborne end integrity monitoring algorithm is used to simulate the vertical protection level(VPL)of single-fault and multi-fault satellites in the BDS andGPS single constellation and BDS+GPS combined constellations,respectively,and refer to different flights.The vertical protection limit(VAL)of the navigation performance requirements of the approach phase,analyzing the integrity performance of the system.