分布式遥感模型库的构建及其运行机制

Construction of Distributed Web-based Remote Sensing Model Library and Its Operational Mechanism

波谱特性是地物目标的基本特性之一,是定性、定量遥感的基础。我国新一代地物波谱库建设以目标地物结构、波谱、知识库、模型库的相互配套为特色,旨在解决以前地物波谱库建设和使用中存在的一些问题,使地物波谱库在空间信息产业化过程中发挥更大的作用。论述了遥感模型库在新一代波谱数据库中的地位和作用,并就遥感模型库的组成、网络环境下的体系结构与开发技术,以及波谱知识库和元数据支持下的遥感模型库运行机制进行了探讨。提出基于网络的三层分布式遥感模型库体系结构和基于组件的模型库构建方法。同时还根据遥感模型库建设的具体情况,讨论了遥感模型方法元数据,并提出基于元数据的遥感模型库管理和运行机制。上述设计思想保证了遥感模型库具有动态的扩充机制和较强的代码可重用性,使模型库能够得到及时更新和扩充,从而保持库的先进性与实用性。

Spectral characteristic is one of the basic characteristics of ground objects, and is the basis of qualitative and quantitative remote sensing. Although we've developed a lot of spectral databases during the past several years, some basic problems still existed in the remote sensing applications, such as the problems of same objects but with different spectra or the opposition, are still not solved completely, which have severely obstructed the development of remote sensing application and industrialization. The main reason lies in that we haven't paid enough attention to the structure, material, and aspection of the measured objects before, and the constructed databases are short of supports of remote sensing models, so the measured data in the databases can't be extended to other cases. The new generation spectral database will be featured by the matching of ground objects' structure, spectra, knowledge library, and model library. Its aim is to solve problems confronted in the previous spectral databases. In this paper, we state the status and function of remote sensing model library in spectral knowledge library, and discuss its structure, system architecture and development technique under network environment. Its operational mechanism under the support of spectral knowledge library and metadata is also discussed. We put forward the web-based three-tiered distributed system architecture and component-based construction method of remote sensing model library. Meanwhile, we also discuss the definition of model metadata from the point of view of remote sensing model library,and put forward metadata-based management and operational mechanism of remote sensing model library. Finally, an application instance and some key codes are presented in the paper.The construction of distributed Web-based remote sensing libraries will greatly enhance the functions of spectral databases, and expand their usable ranges. The component-based design philosophy and metadata-based application and management method ensure that the model library can be updated and modified dynamically to keep its progress and practicability and enhance the reusability of codes.