User Reliability Level Determination for Port PNT Integrity Monitoring Service

Abstract

This paper focuses on a method for the level determination of reliability and its feasibility assessment to support safe ship navigation using the quality and integrity monitoring analysis of GPS/DGPS signals in port environment. At user aspect, it analyzes the position accuracy and integrity performance as comparing to the performance requirement on Harbor Entrances and Approaches (HEA). As a preparation for the performance requirement of IMO’s maritime service, using the field raw measurement data of the Position, Navigation, and Timing (PNT) integrity monitoring system installed in port area, this paper performs the integrity assessment in position domain through analysis of relations about Horizontal Protection Level (HPL), Alert Limit (AL), Position Error (PE) and the quality monitoring in range domain of GPS/DGPS signals of the port user aspect. Based on the quality and integrity monitoring assessment of GPS/DGPS signals, after determining user reliability level, the results are provided to onboard navigational system in real-time based. This paper presents the result of performance assessment using the real-time field raw measurement data in the port environment, and it takes account of the feasible application of port PNT integrity monitoring service through the result analysis.