基于三维虚拟地球的海洋环境数据动态可视化研究

发布时间：2019-06-22 07:43

【摘要】：随着“数字地球”、“数字海洋”等信息化建设的逐步深入推进,人们对于基于地理信息进行海洋信息多维动态可视化表达的应用需求显著增加。海洋环境数据具有海量、多源、异构、数据格式多样、多维、动态等特性,使得对海洋信息的处理与陆地GIS的处理方法大不相同。如何有效地组织、进而高效地多维动态可视化展示、表达这些海洋数据,使人们能够直观地感受到海洋信息的内容,是海洋信息可视化研究的关键技术之一。本文对陆海一体化混合地形渲染模型和面向过程建模的海洋时空过程数据模型研究的基础上,基于真实DEM数据构建的三维虚拟地球,探讨真实多维动态海洋环境数据的可视化思路及具体实现方法,设计并实现了面向服务架构的海洋三维可视化原型系统,对相关关键技术问题进行了有效验证。论文的主要工作和获得的成果如下： (1)探讨基于离散点集的海底DEM生成方法,形成由海洋离散水深点和相关特征点生成较高分辨率海底地形数据的完整流程；针对陆地、海底地形数据的空间尺度差异、分辨率差别等区别,以高效、快速、逼真的一体化三维展示为目标,设计多分辨率地形渲染模型的分层管理机制,提出基于四叉树的改进混合型陆海地形表达模型,实现多种地形模型的统一整合渲染；研究任意形状高分辨率地形数据的混合绘制算法,提高局部高精度地形的三维表达效果。 (2)综合分析海洋环境数据特点和典型海洋环境时空数据模型的基础上,针对三维虚拟地球中海洋时空数据的可视化需求,提出面向过程建模的海洋时空过程数据模型,为海洋时空过程的有效表达奠定基础。采用网络通用数据格式(Network Common Data Format, NetCDF)多维数据组织模型,研究基于NetCDF的海洋环境数据组织方法与存储技术,实现海洋环境数据的统一描述和存储管理,为海洋数据的高效管理、共享进行了有益的尝试。 (3)基于三维虚拟地球,以海洋时空过程模型和NetCDF组织的多维海洋环境数据为基础,研究海洋标量场数据的多模式、多种类可视化表达与分析方法,详细论述海洋时空过程数据的点、线、面、体过程动态可视化,重点研究了基于图形处理器(Graphic Processor Unit, GPU)加速的光线投射体绘制方法；实现三维虚拟地球中标量场数据的剖面绘制、等值线绘制以及等值面绘制等,同时,基于时间插值讨论了海洋时空过程在时间维的连续平滑可视化。另外,基于改进的三维箭头点图标绘制方法实现三维虚拟地球中矢量场的高效动态可视化。在三维虚拟地球中通过多种方式的可视化表达和分析,直观、形象地展示了海洋要素和现象的时空分布和变化情况,为揭示海洋现象的规律和特征提供了可视化途径。 (4)依托现有三维地理信息可视化平台构建面向服务的海洋三维可视化原型系统,基于本文的相关研究,实现陆海基础地理空间数据和海洋环境数据的一体化三维展示与分析,通过一些典型数据的可视化应用实验,对本文所提理论、技术和方法进行了验证。
[Abstract]:With the development of "digital earth", "digital ocean" and other information-based construction, there is a significant increase in the application demand of multi-dimensional dynamic visual representation of ocean information based on geographic information. The marine environment data has the characteristics of mass, multi-source, heterogeneous, data format, multi-dimensional, dynamic and so on, so that the processing method of the ocean information is very different from that of the land GIS. It is one of the key technologies in the research of ocean information visualization. In this paper, on the basis of the study of the land-sea integrated terrain rendering model and the model-oriented ocean space-time process data model, a three-dimensional virtual earth constructed on the basis of the real DEM data is presented, and the visualization of the real multi-dimensional dynamic marine environment data and the concrete implementation method are discussed. The three-dimensional visual prototype system for the service-oriented architecture is designed and implemented, and the relevant key technology problems are effectively verified. The main work and achievements of the paper are as follows: (1) a method for generating a submarine DEM based on a discrete point set is explored to form a complete flow of high-resolution seabed terrain data generated by a marine discrete water depth point and an associated feature point; and In this paper, the spatial scale difference and the resolution difference of the submarine topography data are distinguished, and the hierarchical management mechanism of the multi-resolution terrain rendering model is designed based on the three-dimensional display of high efficiency, fast and vivid integration, and the improved hybrid land-sea terrain expression model based on the quadtree is proposed. The uniform and complete rendering of a variety of terrain models is realized; the hybrid rendering algorithm of high-resolution terrain data of any shape is studied, and the three-dimensional expression effect of the local high-precision terrain is improved (2) Based on the comprehensive analysis of the data characteristics of the marine environment and the spatial and temporal data model of the typical marine environment, the number of time-and-space processes for the process modeling is proposed for the visual demand of the temporal and spatial data of the ocean in the three-dimensional virtual earth. According to the model, it is an effective expression of the time-space process of the ocean. Based on the multi-dimensional data organization model of the Network Common Data Format (NetCDF), the data organization method and storage technology of the marine environment based on the NetCDF are studied, and the unified description and storage management of the marine environment data is realized, which is beneficial to the efficient management and sharing of the marine data. (3) Based on the three-dimensional virtual earth, on the basis of the ocean space-time process model and the multi-dimensional marine environment data of the NetCDF organization, the multi-mode, multi-type visual expression and analysis method of the ocean scalar field data are studied, and the data of the time-space process of the ocean are discussed in detail. The dynamic visualization of point, line, surface and body process is focused on the method of drawing the ray projection based on the accelerated graphics processor (GPU); the section drawing, the contour drawing and the equivalent surface drawing of the scalar field data in the three-dimensional virtual earth are realized. At the same time, based on time interpolation, the continuity of time-and-space process in the time dimension is discussed. in addition, that high efficiency of the vector field in the three-dimensional virtual earth is realized based on the improved three-dimensional arrow point icon drawing method, In the three-dimensional virtual earth, the spatial and temporal distribution and the change of the ocean elements and phenomena are displayed by visual expression and analysis in a variety of ways, and the laws and characteristics of the ocean phenomena are provided. and (4) building a service-oriented ocean three-dimensional visualization prototype system on the basis of the existing three-dimensional geographic information visualization platform, Three-dimensional display and analysis, through the visualization application experiment of some typical data, the theory, technology and
【学位授予单位】：辽宁工程技术大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：P208

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