EGNOS Performance Along Finnish Coast

Abstract

The purpose of this article is to demonstrate the benefits of EGNOS (European Geostationary Navigation Overlay Service / SBAS in Europe) for the Maritime community and inform about the activities that are ongoing for the provision of EGNOS L1 maritime service. EC (European Commission) and GSA (European GNSS Agency) are assessing an EGNOS L1 maritime service with the objective to complement the existing maritime radio-navigation systems (e.g. DGNSS). Maritime community is interested in using SBAS for ocean waters, coastal waters and harbour entrances/approaches considering operational needs (IMO Res. 1046), especially where there is no back-up infrastructure or in poorly covered environments. EGNOS L1 Maritime Service aims at providing pseudo-range corrections and alert information to the GPS L1 signals for maritime navigation, obtaining enhanced accuracy and ranging integrity information over Europe. In order to ensure a safe use of SBAS by all shipborne receivers, an IEC 61108 standard for SBAS receiver equipment should be published. IEC 61108 is a collection of IEC standards for "Maritime navigation and radio-communication equipment and systems - Global navigation satellite systems (GNSS)". In consequence, EC, GSA, ESA and ESSP are developing guidelines for manufacturers for the implementation of SBAS in shipborne receivers to be compliant with the operational requirements defined in International Maritime Organization (IMO) Resolution A.1046. These guidelines, together with a set of test specifications, intend to support the integration of SBAS in the standardisation process for maritime navigation and radio-communication equipment and systems within IEC framework. One GNSS campaign will be performed along the Finnish coast in order to analyse the EGNOS performance in the border of Northeast EGNOS coverage area. Different types of receivers configured to use SBAS will be on board the vessel to analyse the results. The set of receivers to be used would include maritime receivers, high-end receivers and also new receivers aligned with the future SBAS guidelines. On one side, the EGNOS navigation errors will be obtained with respect to a reference PPP post-processed trajectory. On the other side, the EGNOS availability will be obtained, taking especial attention at the border service coverage area. The EGNOS performance results will be compared with respect to the GPS standalone solution, to verify EGNOS provides an enhanced navigation position. The performance obtained with the receivers will be compared with the operational requirements defined in the IMO Resolution A.1046 (27) to assess the feasibility of EGNOS for some maritime applications. Finally, a deep performance analysis will be done in the Northeast border of EGNOS coverage area for ocean waters, coastal waters and harbour entrances/approaches. Based on the results obtained from a receiver, it will be shown a reliable EGNOS navigation solution with better accuracy than GPS standalone solution. The results aim at confirming that EGNOS L1 service is compliant with the operational requirements defined in the IMO Res. A.1046 (27) for ocean waters, coastal waters and harbour entrances/approaches, being beneficial for maritime community.