Research On Modeling And Visualization Of Marine Environment Spatio-Temperal Data

As the development of China's marine resources utilization, the marine environment monitoring has become an important research topic. During the long-term marine survey and research, prodigious amounts of complex marine environment data featured as multi-source, heterogeneous, multi-dimensional, dynamic in structure and temporal are accumulated. Especially with the development of remote sensing technology, such data has been generated rapidly. It has become a trend to utilize the spatial information technology in the management and sharing of the marine environment comprehensive data in recent years. By analyzing the problems existed in the marine GIS, this paper does research on the key technology of modeling and visualization of marine environment comprehensive data. Pointed out that the current GIS software's deficiency in expressing the marine data, introduced of the latest technology of computer visualization such as scientific visualization, virtual reality simulation, volume rendering and grid computing, to meet the marine environment monitoring visualization application requirements, put forward several practical visualization methods and techniques routes based on GIS, and make application of the technology in practice. Specific study as follows:1. Analyzed the existing GIS data model's deficiency in applying to the marine environment field, put forward a field-based model, a joint model based on the field model and the object model, and snapshot grid model for marine temporal and spatial data. Designed the object-oriented data model which integrated field and feature.2. Discussed the key theories and technologies of the GIS visualization, including: scientific computing visualization, Geo-Visualization, virtual reality simulation, virtual GIS, 3D graphics theory, computer graphics technology, spatial database engine, distributed GIS and grid computing, pointed out the challenges in the expression of marine environment data, and designed a GIS-based visualization technology integration framework.3. Analyzed the importance of the spatial database in a visual system, used the object-relational database Oracle to store marine environment data. Designed the data real time storage and assigning method to meet marine environment monitoring system's requirements. Used the multi-resolution tile pyramid technology, massive data indexing technology, threads-based of real-time scheduling, and other technologies to reach the quickly display requirement of actual application.4. Studied the modeling methods of marine virtual sense, proposed the marine natural environment and artificial entity modeling methods. In order to simulation the 3D marine wave, proposed use of marine spectrum function to structure the random marine wave. Such 2d-based simulation, through to multiple summation of the sine component given by energy spectrum, is easy and feasible, and obtains the good effect in the vision. 5. Researched virtual visualization of marine environment based on virtual GIS. Analyzed the integration of virtual reality technology and GIS, proposed two development strategies of virtual GIS, and pointed out that the loose data combined of virtual reality and GIS is the better integration method. In order to enhance the efficiency and the quality of procedures, simplify the process of modeling and simulation, this article has proposed the loosely-integrated design method based 3D graphics engine, and developed the marine environment 3D graphics engine OE3DGE.6. According to the characteristics of the marine environment application, proposed marine multidimensional dynamic data visualization method. Describe the multi-dimensional characteristics of the space object and its change trend comprehensively, detailed and accurately. Providing marine scientific researcher a visual expression and analysis tools, intuitive expression and to reveal the marine phenomena and structural characteristics, providing the dynamic changes in ocean phenomena, historical retrospective and the visualization of future evolution.7. In order to dynamically display marine environment 3D data in the overall change, proposed the visualization methods of 3D field data based on volume rendering. The scalable solutions based on ArcGIS platform using advanced visualization tool sets VTK of is given, to achieve large-scale real-time dynamic field data visualization, intuitive accurate understanding of the situation of the marine environment.8. For the visualization of marine environmental data in large, compute-intensive, low efficiency, distributed, and other characteristics, proposed the grid-enabled visualization methods. Through the dynamic organization of resources to meet the visual computing applications and data storage needs, designed the multi-grid system architecture for the marine environment data visualization, and discussed the process of the grid-enabled visualization. Taken the volume rendering of marine environment data's as an example, has made the preliminary test of the system.