SBAS Monitoring Platform for ANSPs

Abstract

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 through the monitoring of the GPS satellites and the ionosphere. SBAS systems have already been 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). By its definition, using mainly geostationary satellites, these SBAS services allow to cover large regions which makes that several countries and air traffic regions benefit for a single service. Air Navigation Service Providers (ANSP) are in charge of managing the air traffic in their regions or countries. While agreements among different supranational entities allow coordinating these SBAS systems, ANSPs need a way to independently monitor the SBAS performances within their countries or regions. Beyond legal or political issues, a national monitoring system allows a degree of granularity that will become complex to be performed considering the whole SBAS service area. Having a SBAS monitoring platform for their own network of receivers will allow ANSPs to have a clear view of the SBAS performances at particular locations (mainly airports). By defining certain performance thresholds, ANSPs can be promptly warned about SBAS performance degradations allowing them to make decisions about the usability of SBAS based procedures at those particular locations and times. The present paper describes a commercial SBAS monitoring platform that has been specially adapted for Oro Navigacija (Lithuania) ANSP. This platform was developed by GMV based on proprietary tools used during more than twenty years for the SBAS performance monitoring and considering a set of commercial receivers already deployed by Oro Navigacija in several Lithuanian airports. It was deployed in Oro Navigacija premises in January 2021 and has been continually working and storing data since then. This paper will describe the needed infrastructure in terms of receiver’s network, communications and computing capabilities. It will present the main SBAS performances monitored as well as the alerts generated in order to warn the ANSP of abnormal situations. Additional capabilities, such as the storage of the GNSS collected data for offline analysis, will be also presented. Finally, the paper will summarize the benefits of this kind of monitoring for ANSPs, highlighting the differences with respect to the wide area monitoring that SBAS service providers generate.