Concept for an Onboard Integrated PNT Unit

A robust electronic position, navigation and timing system (PNT) is considered as one of the core elements for the realization of IMO-s (International Maritime Organization) e-Navigation strategy. Robustness can be interpreted as the capability of an integrated PNT system to provide PNT relevant data with the desired accuracy, integrity, continuity and availability under consideration of changing application conditions and requirements. Generally an integrated PNT system is a composite of service components – like GNSS, Augmentation Systems and terrestrial Navigation Systems – and an on-board integrated PNT Unit, which uses the available navigation and augmentation signals in combination with additional data of sensors aboard to provide accurate and robust PNT information of the ship. In this paper a concept of such an onboard integrated PNT Unit will be presented, which is designed to fulfill the specific user requirements for civil waterway applications. At first, the user requirements for an integrated PNT Unit will be overviewed. After that, existing integrity monitoring approaches will be analyzed. Finally, a first integration scheme for an integrated PNT Unit will be presented with a special focus on the internal integrity monitoring concept.