Coordinated Enhancement of the maritime PNT System: �Road Map and Guidelines

Abstract

A reliable knowledge of ship’s position and movement in relation to other traffic participants is necessary for safe navigation at sea. A prerequisite to avoid collisions and groundings is the resilient onboard provision of position, navigation, and time data. This is emphasized by e-navigation solution S3 “Improved reliability, resilience and integrity of bridge equipment and navigation information” and assigned risk control option RCO5 “Improved reliability and resilience of onboard PNT systems” (NCSR1/9). In recent years the modular and open concept of an integrated PNT system has been developed as framework for the coordinated enhancement of the maritime PNT system (NAV58/6/1, NAV58/INF5, NCSR1/9/2). The Performance Standard for multi-system shipborne radionavigation receiver equipment, highlighted in this concept and currently under development (NCSR1/10), provides the basis to enable the full use of data coming from current/future radionavigation systems/services (e.g. range measurements, system parameters and variables such as orbit, correction and augmentation data). Furthermore the concept recognises the demand of an onboard PNT Unit as a synonym for a shipborne data processing tool to facilitate the application of multi-system-/multi-sensor-based techniques for resilient provision of all PNT data and reliable monitoring of data and system integrity (NAV58/6/1, NAV58/INF5, NCSR1/9/2). The combined use of PVT relevant sensors (e.g. GNSS Receiver, DGNSS corrections, Multi-Radionavigation Receiver) and onboard systems (e.g. Radar, Gyro, Echosounder with bathymetric data) establishes the needed redundancy to enable the monitoring of data and system integrity and to improve the performance of provided PNT data. This enables the protection of the onboard process of PNT data generation (cybersecurity) against intrusions by malicious actors. Therefore the drafting of a Guideline for the PNT Unit is considered as a supplementary but necessary step in the overall PNT system development for e-navigation solution S3 and associated risk control option RCO5. Reliability, integrity and resilience are fundamental requirements on nautical onboard equipment/systems identified as user needs and addressed as high-priority solution in the frame of e-navigation. If the PNT data provision meets these fundamental requirements or not can only be evaluated with respect to specific sets of technical requirements. To determine the achieved degree of reliability it is necessary to specify the tasks/functions to be performed by the equipment/system, the nominal operating conditions incl. dependencies on external systems/services and the required interruption free period of time. To achieve standardized results for integrity evaluation it is necessary to specify the methods of integrity monitoring in an unambiguous manner. And to ensure resilience it is necessary to identify the demand on intrasystem error compensation in relation to specified tasks, functions and performance requirements. The development of a guideline for the onboard PNT Unit is an appropriate measure to point out and clarify the dependencies between available/usable system modules (e.g. sensors, services, data sources) the applicability/feasibility of system operation (tasks, functions) and the achievable quality of data products.