Maritime GNSS navigation local error sources characterization

Maritime transport, including fluvial navigation, has a very important role for European trade and connection of the states. Position, Navigation and Timing (PNT) information at sea represent part of the critical navigation data ensuring safety and security of transportation. This information, provided mainly by Global Navigation Satellite Systems (GNSS), can be affected by local error sources, such as multipath and radio frequency interference. In this context, an assessment of the local errors affecting PNT information in maritime environments for different operational scenarios is of high importance.

The MARGOT project, developed by a consortium led by RISE was selected by the European Space Agency to respond to the Multipath & Interference Error Mitigation Techniques for Future Maritime e-NAV Services initiative. The project aims to monitor the GNSS environment in real life maritime navigation services, to develop models and methods for mitigation against errors in positioning. The project started in February 2018 and was finalized in September 2020.

Multiple data collection campaigns were performed using three vessels of different sizes. The campaigns included fluvial navigation (on the Danube), coastal and open sea navigation (in the Black Sea and Aegean Sea), port and port approach navigation in several ports from Romania. The equipment on board included two types of GNSS receivers and two types of antennas, a Software Defined Radio and an interference detector. In total, an amount of approximately 2800 hours of data were collected.

The analysis of the local errors took into consideration several influencing factors, such as the type of navigation, the type of the ship, the type of receiver and antenna, the location and height of the antenna and the state of the sea. The effects of these errors were modelled using 80% of the collected data, while the remaining 20% was used for model validation.

The results of the project include a set of conclusions regarding the impact and relevance of the categories of influencing factors with respect to the local error sources and a set of recommendations for future regulations in the maritime domain.

The activities and results of MARGOT were presented at the ION GNSS+ conference, which was held between 21st and 25th of September 2020. The presentation was selected the best presentation of the Marine Applications and Search and Rescue session.