PNT-data generation as basis for guidance systems in inland water traffic

The use of Global Navigation Satellite Systems (GNSS) in maritime applications has been widely recognized as an essential part of maritime navigation. This is due to good reception conditions on open water and due to the low accuracy requirements when navigating on the open sea. When it comes to inland waterways, GNSS is an important tool for the measurement of navigational data and position. In this context, a reliable navigational solution is the base for the implementation of applications for advanced assistance during berthing or bridge and lock passing. However, exactly these applications pose a challenge to a GNSS-based positioning solution, since the critical navigation-areas are often also those with restricted reception conditions. To ensure continuously accurate position navigation and timing (PNT) data, a so called PNT-Unit has been designed based on the fusion of GNSS, inertial (Inertial Measurement Unit - IMU) and other ship-borne sensors. One of the goals of the project PiLoNav (Precise and Integer Localization and Navigation in Rail and Inland Water Traffic) is the development of a manoeuvre guidance system tailored for these critical scenarios. Since the driver assistance will be based on absolute positioning, a precise survey of the environment is required as well as the precise vessel position and navigation states. While the first is a question of the quality of the underlying map the determination of latter parameters proves difficult.