Lessons Learned from SBAS Systems and Testbeds for the Global SBAS Concept

Julián Barrios, José Gabriel Pericacho, Javier Arenas, John Xihua Liu, Susana Domenech, Jose María Bernárdez, Guillermo Tobías, Robert Jackson, Patrick E. Reddan, Deane Bunce

Abstract:	The Satellite-Based Augmentation Systems (SBAS) provide safe civil aviation navigation services for En-route through LPV-200 precision approach operations. Current operational L1 SBASs improve user accuracy and integrity over specific regions by monitoring the GPS satellites in conjunction with ionosphere effects on GNSS signal propagation. The SBAS systems are currently going through a modernization process derived from, firstly, its implementation of new regions and, secondly, the development of the future SBAS DFMC services allowing the processing of constellations beyond GPS and supporting dual-frequency users. Also, the SBAS modernization is exploring synergies with other services such as PPP. Through this approach, the SBASs increase the added value provided by its infrastructures and enable new services beyond the initially targeted civil aviation domain. SBAS systems have been already commissioned and operated in the United States (WAAS), the European Union (EGNOS), India (GAGAN) and Japan (MSAS). Additionally, SBAS deployments are currently underway in other regions, including Australia and New Zealand (SouthPAN), China (BDSBAS), Korea (KASS), Russia (SCDM) and Africa (ASECNA). This paper measures and compares SBAS systems performances including, WAAS, EGNOS, GAGAN, MSAS/QZSS, SDCM, Australia and New Zealand SBAS Testbed, ASECNA, ASAL and BDSBAS. The SBAS messages are processed to obtain a statistical characterization of the constellation satellites and ionosphere information. The metrics considered include 15-min sampled range user error, UDRE bound ratios, GIVD accuracy and GIVE bound ratio over the long-time historical data. While this comparison does not intend to benchmark one system’s performance against another, it can show at which level the SBAS accuracy can support other services and how civil aviation requirements drive the confidence interval of the integrity information. The current status of the SBAS systems and Testbed is used to analyse lessons learned towards the Global SBAS concept promoted over the last few years by Lockheed Martin and GMV. The Global SBAS combines the advantages of traditional SBAS and PPP technologies to satisfy aviation and other service needs while distributing the infrastructure and operation costs among a global user community. The Global SBAS concept readily offers global services allowing countriesto reduce capital and operational expenditure compared to traditional SBAS solutions.
Published in:	Proceedings of the 34th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2021) September 20 - 24, 2021 Union Station Hotel St. Louis, Missouri
Pages:	1516 - 1549
Cite this article:	Barrios, Julián, Pericacho, José Gabriel, Arenas, Javier, Liu, John Xihua, Domenech, Susana, Bernárdez, Jose María, Tobías, Guillermo, Jackson, Robert, Reddan, Patrick E., Bunce, Deane, "Lessons Learned from SBAS Systems and Testbeds for the Global SBAS Concept," Proceedings of the 34th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2021), St. Louis, Missouri, September 2021, pp. 1516-1549. https://doi.org/10.33012/2021.17875
Full Paper:	ION Members/Non-Members: 1 Download Credit Sign In