北斗卫星空间信号故障与监测性能指标定义

卫星导航系统指标分配与论证是指导和约束各大系统方案设计及工程实现的重要依据.完好性和连续性是系统服务性能的关键指标，能否满足用户需求主要取决于其中的空间信号故障和监测性能指标.以用户完好性和连续性要求为设计依据，定义了空间信号故障次数、平均故障率、故障漏检率、虚警率等系统指标与完好性、连续性等风险概率之间的转换关系.针对北斗系统及星座构成特点，按照国际民航组织规定的用户完好性和连续性风险概率需求，分析了不同空间信号故障条件对系统完好性监测性能的指标要求.研究结果可为北斗全球系统可靠性指标论证和设计提供依据和参考. 

Fault and Detection Performance Definition of Beidou Satellite Space Signal

Performance index assignment and demonstration is an important accordance for satellite navigation system, and it is necessary to direct and restrict each system scheme design and project implementation. Integrity and continuity are key service performance indexes, and whether they are satisfied with user requirement depends on the design of SIS (Signal in Space) fault and monitoring performance. In the system index design, the fault rate of satellite signal and the integrity monitoring index of satellite signal are complementary and constrained with each other. It is necessary to realize the comprehensive design according to the index of each link of the system. Taking user integrity and continuity performances as designing accordances, the conversion and distribution relationships among SIS fault times, mean fault probability, fault misdetecting probability, fault alarming probability and hazardous probability are defined. Then calculation and analyzation are implemented aiming at Beidou system and its constellation characters. In the calculation, requirements of user integrity and continuity adopt the ICAO standard, and the level of satellite signal failure refers to the actual operation level of Beidou regional system. Beidou system monitoring performance index under different SIS fault level is analyzed. The research conclusions provide demonstration and design foundation of the reliability index for Beidou global system.