Abstract: Ship visualization and analysis play an important role in the field of modern navigation management. In view of the disadvantages of the current mainstream ship symbol expression, such as distortion and difficulty in interaction. This paper proposes a vector plotting method for real-time dynamic data of ships in large space range. We implement real-time access to ship data streams for creating a continuously updated ship feature service based on spatio-temporal GIS technology. The front-end program establishes two-way communication with the service through WebSocket, obtains the latest ship positioning information with low latency, and combines multi-spatial scale expression rules and plotting algorithms for symbol redrawing to achieve accurate expression of ship position, size, and heading under different display levels. Tests have proved that this method can effectively support the dynamic visualization of ship data in a large geographic area and meet the needs of ship collision avoidance, maritime management and application analysis.

Key words: ship visualization, real-time data, vector plotting, spatio-temporal GIS, symbolic expression rules