Initial investigations for building a prototype GBAS operating with multi constellation and GNSS multifrequency

Abstract

The GBAS (Ground Based Augmentation System) is an augmentation system that is responsible for ensuring the maintenance of quality parameters (accuracy, integrity, continuity, and availability) related to GNSS (Global Navigation Satellite System) positioning applied in aviation. This system makes use of a set of GNSS stations, located around the airport, integrated with a communication system and with models to assess integrity, used in aviation that assists in precision approach procedures. GBAS is based on the DGNSS (Differential GNSS) positioning method, in which reference stations generate phase-smoothed pseudo-distance corrections that are transmitted to the aircraft and thus improve the accuracy in determining its position. According to the ICAO (International Civil Aviation Organization), the GBAS is authorized to operate using only the L1 frequency of GPS and GLONASS, since for security reasons the L2 frequency is not authorized as it has no guarantee of integrity of this one that is not part of the spectrum protected by aviation bodies. The trend is that, in the future, GBAS will be guaranteed to operate using two frequencies (L1 and L5), in addition to possibly making use of two or more constellations to perform GNSS positioning. This work aims to initiate an investigation for the development of a GBAS prototype capable of operating with multi-constellation and multi-frequency GNSS, in addition to evaluating its use in air navigation. (AU)