GNSS Integrity and Receiver Autonomous Integrity Monitoring (RAIM)

This chapter describes the concept of integrity for global navigation satellite system (GNSS) applications. It defines integrity in the context of other navigation system parameters and explains the trade‐off between integrity on one hand and continuity and availability on the other. The chapter also explains the key variables used to quantify integrity and discusses the context in which integrity risk probabilities are estimated. It explores how and why integrity is evaluated by users in real time by computing protection levels for the position, velocity, and time outputs that matter to particular applications. The chapter examines the building blocks of protection level calculations: rare‐event bounds under nominal conditions and bounds under faulted conditions. It shows how these principles are applied to the design and analysis of receiver autonomous integrity monitoring, which is a monitoring technique that exploits redundancy in user measurements and is applied by both stand‐alone and augmented GNSS users.