Abstract: The emergence of satellite based augmentation system(SBAS) can effectively improve the performance of the core constellation of global satellite navigation system. Especially in the field of civil aviation, SBAS has been widely used because it can generate higher-precision positioning and provide safer navigation services. With the measured data of navigation and augmented messages from different monitoring stations in the SBAS service area, the positioning accuracy and integrity message processing process, as well as the integrity parameter indexes such as visible star quality, positioning error, protection level and alarm threshold are studied. Targeting at the fault detection capability of integrity monitoring, the paper analyzes the integrity service performance of the satellite under different fault functions, and finally detects and eliminates the errors of SBAS. The results show that according to the decoding of the message and the algorithm of parameter extraction, better accuracy and integrity results can be obtained. The precision of each monitoring station can meet the requirements of LPV-200. The local ground station meets the integrity requirements of the LPV-200 approach by 100%, and remote stations all meet the integrity requirements of the LPV approach except for a few moments. After error elimination, the service performance is basically similar to that without failure.

Key words: satellite based augmentation system(SBAS), positioning error, protection level, alarm threshold, integrity failure