Gras development, approval and implementation in Australia

This Thesis covers the development of an alternative Global Navigation SatelliteSystem (GNSS) augmentation technology that has become known as the Ground-basedRegional Augmentation System (GRAS). GNSS augmentation technologies in support ofaviation have largely been developed by countries with large economies such as the USA andmembers of the European Union. These technologies have focussed on solutions to thespecific problems of the host nations, based on the demographics, political and economicfactors relevant to them. Outside these countries, the role of GNSS augmentation has largelybeen ignored, specifically when considering wide area augmentation utilising Satellite BasedAugmentation Systems (SBAS). SBAS technologies are expensive, and cannot be justifiedfor nations like Australia with a relatively small number of aircraft, operated in a focussedgeographic area. Utilising SBAS services provided by another country introduces cultural,legal and institutional issues that are not always easily addressed. GRAS was derived toprovide a cost-effective wide area augmentation capability to nations that lacked theeconomic ability to field SBAS technologies.This work covers the evolution of the GRAS concept, the construction and testing ofthe GRAS test bed and its associated test avionics, as well as the development of standardsneeded to support GRAS as an internationally accepted aviation standard.The major outcome from this work was the confirmation that GRAS could meet theRequired Navigation Performance (RNP) standards for Approaches with Vertical GuidanceLevel 2 (APV-II) as well as all less demanding modes of flight. Results from numerousground and flight tests conducted under this research program have been reviewed by theInternational Civil Aviation Organisation (ICAO) GNSS Panel (GNSSP), and beeninstrumental in the development and validation of Standards and Recommended Practices(SARPs) which promulgate how ICAO standardised systems should perform.The final component of this work describes the project management and technologyapproval processes needed to get an internationally standardised system into operational use,and the particular problems that a small country like Australia has in progressing these taskson the World stage