GNSS and GEO Signal Integrity

Abstract

Global Navigation Satellite Systems (GNSSs) have both internal and independent methods to maintain integrity. This chapter discusses two different methods– GNSS‐ receiver autonomous integrity monitoring and use of ground monitoring stations to monitor the health of the satellites, as is done via space‐based augmentation system (SBAS) and the ground‐based augmentation system. SBAS integrity is based on the premise that errors not detected or corrected in the operational environment can become threats to integrity and, if not mitigated, can become hazards to the user. The user must be protected from residual errors that can become threats to the integrity data that could result in hazardously misleading information being transmitted to the user. The SBAS system must compute estimates of the reference receiver clocks and GNSS/geostationary Earth orbit satellite clock errors. The chapter also describes some approaches that may be used to eliminate and minimize data errors, mitigate integrity threats, and satisfy the safety integrity requirements.