SBAS DFMC Analysis with a Software Prototype

Daniel Salos, Mikael Mabilleau, Catalina Rodriguez, Hugues Secretan, Norbert Suard, François Dufour, Philippe Estival

Abstract:	The GNSS environment for civil aviation is evolving towards a Dual-Frequency Multi-Constellation (DFMC) scheme thanks to the deployment and modernization of multiple GNSS constellations (modernized GPS, Galileo, GLONASS, Beidou) broadcasting dual-frequency signals in the Aeronautical Radio Navigation Service bands. This new GNSS scheme will support in the coming years aeronautical navigation services with improved positioning performances and robustness. The definition and analysis of the GNSS augmentation systems evolution to operate in this new dual-frequency multiconstellation (DFMC) environment is on-going. In the case of the SBAS evolution, the SBAS Interoperability Working Group (IWG) has worked on the development of an SBAS DFMC L5 Interface Control Document (ICD) in order to initiate the standardization of the future SBAS DFMC system and services. Other working groups such as the EUROCAE WG-62 and the RTCA SC 159 have also started the development of standards to support the introduction of future SBAS DFMC user receivers. The SBAS DFMC Service Volume software Prototype (SBAS DSVP) is a tool compliant with the latest SBAS DFMC L5 ICD produced by the IWG and developed to support SBAS DFMC standardization activities. The prototype generates the sequence of broadcast SBAS DFMC messages as well as the broadcast parameters required to analyze the availability and continuity of APV and CAT I operations in the SBAS service area. The prototype’s user module is able to compute Horizontal and Vertical Protection Levels (HPL/VPL) from the SBAS L5 messages elaborated by the ground module. The behavior and performance of SBAS DFMC systems as defined in the latest IWG documentation have been analysed with the SBAS DSVP for different system configurations. The performance analysis is based on different indicators such as the service availability and continuity, the bandwidth occupation by the different Message Types or the time to first valid position fix (TTFF). Different system configurations have been analyzed, including different augmented constellations and ground station networks. The analysis is focused on the impact of the following elements: a) the strategy selected to broadcast integrity information to users, b) a potential single-frequency L5 SBAS back-up service, and c) the presence of equatorial ionospheric scintillation.
Published in:	Proceedings of the 30th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2017) September 25 - 29, 2017 Oregon Convention Center Portland, Oregon
Pages:	2019 - 2030
Cite this article:	Salos, Daniel, Mabilleau, Mikael, Rodriguez, Catalina, Secretan, Hugues, Suard, Norbert, Dufour, François, Estival, Philippe, "SBAS DFMC Analysis with a Software Prototype," Proceedings of the 30th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2017), Portland, Oregon, September 2017, pp. 2019-2030. https://doi.org/10.33012/2017.15322
Full Paper:	ION Members/Non-Members: 1 Download Credit Sign In