机载SBAS接收机完好性服务性能分析

Analysis of integrity monitoring performance of airborne SBAS receiver

星基增强系统(SBAS,satellite based augmentation system)的出现可有效提升全球卫星导航系统核心星座的各项性能,因其能够产生较高精度的定位信息以提供更加安全的导航服务,被广泛应用于民航领域中。利用SBAS服务区域内不同监测站接收的导航和增强报文等实测数据,研究了定位精度和完好性报文处理过程以及可见星质量、定位误差、保护级和告警门限等完好性参数指标。针对完好性监测所要求的故障检测能力,分析不同故障函数时卫星的完好性服务能力,最后完成SBAS故障卫星的检测与排除。结果表明:根据报文解码及各项参数提取算法能够得到较好的精度和完好性结果,各地面站精度都符合LPV-200进近时的要求;美国本土中部地区完全满足LPV-200进近的完好性服务要求,边缘地区监测站除个别时刻外均满足LPV进近的完好性服务要求;排除故障卫星后,服务性能基本与未发生故障时性能相近。

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.