Fundamentals of Integrity Monitoring

This chapter describes the methods of integrity monitoring, necessary to verify if all the satellites involved in the PVT computation are healthy or not. In particular, we will see the solution adopted by a stand-alone receiver equipped with a system able to check if the hypothesis of nominal conditions (i.e. when all the satellites are healthy) can be considered valid. This is a fundamental step before evaluating the confidence interval associated to the estimated position. The reason why integrity monitoring is a necessary step for the evaluation of the confidence interval is briefly described in Sect. 3.1, while the remainder of the chapter is devoted to the methods of fault detection (FD), and fault detection and exclusion (FDE), generally implemented in the algorithms of receiver autonomous integrity monitoring (RAIM) systems.