Ground-based Augmentation System (GBAS) is a safety-critical satellite-based aircraft precision approach and landing system, and supports all phases of approach, departure, and surface operations. The ICAO Standards and Recommended Practices (SARPs) for GBAS provide the safety requirements, i.e. integrity, continuity, and availability, as well as the system accuracy. The ENRI GBAS ground prototype system (Category-I) was developed to realize the safety requirements through a safety design process based on the probabilistic safety assessment (PSA), and includes the integrity monitor algorithms (e.g. GPS satellite signal deformation, low power, code-carrier divergence, excessive clock acceleration, erroneous ephemeris broadcast, ionospheric delay) in the risk mitigation.
The purpose of this paper is to describe the summary of a safety design process including an example of integrity monitor algorithms, and a validation method for the safety assurance performed through the development of this system. This paper provides the worst-case simulation result of performance validation for the signal deformation monitor algorithm using the long-term real data which is collected by the prototype system installed at Kansai International Airport.
