Research Of 3D Visualization In Offshore Based On ENC

The ECDIS(Electronic Chart Display and Information System) is an integrated system, which integrated many subsystems based on the ENC data sets which accords with the IHO S-57 standard. These subsystems included electronic chart displaying system, locating system etc. The system has many functions, for example displaying ENC, making routing plan, recording marine data. These functions improve maritime safety. But the current ECDIS is emphasizing particularly on 2D model design and displaying, especially to a lot of 3D information which can only be visualized in 2D symbol or number under ECDIS. The 2D model can't reflect such real sail environment intuitively and rapidly as seabed under kneel, island or mountain's shape, and the visual environment under a ship's kneel which constrained by her draught. But, at same time, there is much data in database of ECDIS or maritime precaution from nation's marine department, which can be displayed intuitively and real-time in 3D model, for example 3D sounding data, real-time water-level and tide information precaution from nation's marine department etc.The thesis, which is based on the project of National Science Fund — Behavior-Characteristic modeling for Distributed & Interactive 3D Scenery, research the technology of 3D visualization in offshore based on ENC data sets. It includes the DEM model of the seabed, dynamic simulative sea-surface, and shape or signal light model.The data source must be taken into account firstly before visualize in offshore. In chapter 4, I give some detailed analysis about data source, data model and its file structures. Then two methods are introduced to access data in ENC data set. One is a created whole database which can be filled with all data read from the ENC data set file, the other is just reading the data which will be used in this thesis. The latter is adopted in my thesis.After finish reading 3D sounding data from the ENC data set file successfully, I analyze how to create the TIN model which accord with Delaunay regulation in chapter 5. From the TIN Model, we can see clearly that TIN model is very rough. So Iuse Moving Average arithmetic which is one of the spatial data interpolations to create more precise DEM model of the seabed. And it is girding method of discrete data analyzed in chapter 5. To the navigation surface model, I select sine wave superposition technology to create dynamic sea-surface and adopt 3D modeling tool to create the model of the shape. At the end of the thesis, I select lens flare technology to create the signal light model to increase the realistic of the visualization scenery.