主动式地理信息系统的实现与应用

提出分布式环境下,由于空间数据表达对象的分布性、数据来源分布性和空间信息服务对象的分布性特征,决定了空间信息服务技术系统--GIS具有分布式的特点,另一方面空间信息服务在许多应用领域又具有实时性要求,这两个特点产生了一个矛盾,也就是空间信息服务系统的分布性特征与信息服务的实时性要求的矛盾。为了解决空间信息服务系统的分布性特征和信息服务的实时性之间矛盾,本文首次提出了主动空间信息服务的思想和概念,并在此基础上提出了实现主动空间信息服务的支持技术--主动式地理信息系统的概念,以分布式地理信息系统的单个节点为例,提出了主动式地理信息系统的软件体系结构和主动服务的规则,主动式地理信息系统节点(GIS)包括一个传统的地理信息系统、一个事件驱动知识库和一个事件监视器三部分构成;主动功能的实现需要是由事件监视器监视相关事件的发生,并依据事件驱动知识库中的主动服务规则执行相应的功能。提出了主动式地理信息系统中基本事件和事件表达式、事件运算的方法以及复杂事件的表达等,对主动服务的实现途径以及关键技术进行了研究。结合某企业综合资源GIS系统的研究对主动式地理信息系统的体系结构、实现途径和关键技术等进行了试验,实验结果表明,主动式地理信息系统可以有效地提供实时空间信息服务。

Research on Active Spatial Information Service

In the distributed environment, the existence of the distributed features in the presented object of spatial data, the source of the spatial data and the object of the spatial information service decided that GIS had the distributed feature, too. Meanwhile, the spatial information service has the demand of real time. The active spatial information service is the necessity for overcoming the illogicality between the distributed feature and real time of the spatial information service. Firstly, to resolve this illogicality, this paper advanced the conceptions of active geographic information and active geographic information system. Secondly, it advanced the architecture and active service rules of the active geographic information system by taking node of the distributed GIS as an example. Thirdly, it considered that a node of the active GIS includes a typical GIS, an event driven knowledge base and an event monitor. The realization of the active function depended on the event monitor scouting some event's arise and active service rulers in the event ruler base. Finally, it advanced basic event and its expression, event operation's methods and the expression of complex event, and studied the realization approaches and key technologies of the active geographic information system. The architecture,realization approaches and key technologies had been tried in an application GIS. The experiments indicated that the active geographic information system is efficient for providing real time spatial information service in the distributed environment.