PNT (Position, Navigation, Timing)

Position, Navigation, and Timing, the combined capability that answers where a platform is, how it gets to its destination, and the precise time, underpinning shipboard and port operations. GNSS is the dominant PNT source, but reliance on a single weak signal is a known vulnerability, so resilient PNT layers in DGNSS, eLoran or R-Mode terrestrial backup, inertial systems, and multi-constellation receivers. IMO Resolution A.915(22) set the maritime PNT policy and user requirements; PNT also times AIS, synchrophasors, and port automation. Timing failures cascade as silently as position errors.