Reliable vessel navigation system based on multi-GNSS

One of the most recent aims established by IMO (International Maritime Organization) is the improved reliability and integrity of navigation information, in order to enhance navigation safety and security services at sea. Actually, the GPS (Global Positioning Systems) and AIS (Automatic Identification System) provide ship position, speed and course to VMS (Vessel Management System) platforms, without any consideration about the safety and security. The reliable navigation system proposed is based on a multi - GNSS satellite receiver and on vessel speed log and direction finder (magnetic or gyro compass). The robustness of navigation solution in ensured by: RAIM (Receiver Autonomous Integrity Monitoring) algorithms able to avoid (or limit) the consequences of gross errors between measurements, and by a coherence check between GNSS and position solution provided by a Dead Reckoning algorithm, based on log and compass measurement, able to highlight drift in position domain, caused for example by spoofing on GNSS receiver. In order to validate the algorithms, several tests have been carried out in different scenario, in static and kinematic condition.