Thoughts on Key Technologies of Underwater PNT System

Due to the inherent characteristics of the marine environment and seawater medium, users cannot effectively use satellite navigation systems for positioning, timing, navigation and communication in the underwater environment. The autonomous, continuous, unified and accurate underwater PNT information faces significant challenges compared with the surface and space environment. There are still several critical technical bottlenecks that need to be broken. This paper presents the comprehensive application prospect of the underwater PNT system. It summarizes and analyzes the application and technology development status of the Underwater PNT system at home and abroad. It also puts forward the basic construction idea of the underwater PNT system based on various navigation methods such as inertial, acoustic, matching and radio. It points out the critical technical bottlenecks that are difficult and urgent to be breakthrough in the front. It also provides a reference for building a more ubiquitous, integrated, intelligent, and comprehensive PNT system.