摘要
在数值天气预报中，会产生大规模的科学数据，如何分析、可视化大规模科学数据给可视化研究带来了挑战。随着Internet的飞速发展，在网上发布气象信息，应用网络进行交互式合作，基于Web的可视化成为气象可视化应用的一个重要方向。本文研究了基于Web的四种可视化参考模型，在三层客户／服务器计算模式上设计实现了一种可视化Web服务器架构，并实现了基本功能。
科学可视化的核心是三维数据场的可视化，气象数据是一种典型的多时序、多变量的三维空间数据场。三维空间数据场的可视化方法有：传统的二维数据场可视化方法，通过切片方法运用到三维数据场中；利用三维图形、动画效果的可视化方法，如等值面、流线、迹线等方法来进行数据可视化；以及直接体绘制方法。本文研究了这些算法在可视化系统WebMVS中的具体实现。
在基于Web的气象可视化系统设计中，需要重点解决的是远程对象的访问，本文中采用的是Corba与Java相结合的Java RMI(Remote Method Invocation)。RMI为服务器和客户机进行通信和消息传递提供了一种机制，以可执行代码重用形式，通过定制的系统行为和接口规范，有别于传统的客户机／服务器模式。
In the Numerical weather Pridiction,large-scale scientific data will be generated. With rapid developments of the internet,spreading meteorologic information on the internet and interactive collaboration with the internet has become popular. So,web-based visualization turns out to be an important field of meteorologic visualization. This paper addresses the four reference model of Meteorologic Visualization System(MVS) and has implemented the basic modules of MVS.
The kernel of Scientific Visualization is the Visualization of three-Dimension data field. The data field of Meterologic application is the multi-timestep,multi-variable 3D space dataset. The visualization methods of 3D data-field includes:the visualization methods of 2D datasets,the visualization methods with the 3D graphics elements,the direct volume rendering of datasets. These algorithms are introduced in this paper and realized in the Meterologic Visualization System of WebMVS.
In the realization of web-based MVS,it is of great importance to solve the problem of access to remote object. Java Remote Method Invocation which is the combination of Corba and Java is adopted in this paper. RMI provides a mechanism of communication and message passing between client and server. The mechanism is fulfilled with the reuse of executable code. The code has customized system behavior and interface criterion. So,the mechanism is different from the traditional client/server model.
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