【作者】 李文全；

【导师】 李峰；

【作者基本信息】 江苏大学 ， 计算机应用技术， 2006， 硕士

【摘要】 分布式异构空间信息的共享是当前GIS应用的研究热点，其中，解决空间数据的格式、结构和语义的不一致，实现多数据源的有机集成是其中的关键问题之一。本文采用互操作集成模式，通过引入GML、SVG、元数据和Web Service技术，解决了异构数据的可达性、集成系统的可伸缩性、数据互操作等问题，为用户提供了较好的信息服务，并初步实现了分布式、异构、自治、海量的空间信息的有机集成，同时通过引入二次缓存技术，明显提高了系统的整体性能。本论文的主要研究工作有：(1)深入研究了GML的数据表现能力和应用扩展能力，分析了GML技术在多数据源集成系统中的应用优势。根据遗留空间信息的现状，讨论了空间信息向GML数据的转换、GML文档的解析和查询技术的实现方法。(2)在深入研究了SVG技术的地图表现能力的基础上，分析了XSLT的转换方法，并根据GML和SVG空间信息图元的对应关系，编写了相应的XSLT转换模板。(3)研究了Web服务和元数据技术的工作原理，分析了它们在多数据源集成系统中的应用方法，探讨了它们解决数据可达性和用户快速定位问题的实现方案。(4)分析了当前数据集成系统的性能问题，提出对GML文档的两次缓存思想，讨论了缓存模块的管理、替换策略和一致性问题。(5)针对城市交通管理的应用需求，设计并实现了多数据源集成原型系统。该系统在结构上分为应用层、数据集成层、服务层和数据层，各层之间通过Web协议调用，基本上实现了集成分布式异构空间数据的目标，并具有较高的响应性能。通过对原型系统的建立和缓存性能的分析，进一步论证了面向多数据源的WebGIS的可行性，为实现空间信息的共享，集成大规模的数据提供了一个新的集成思路。更多还原

【Abstract】 The share of heterogeneous and distributed spatial information is the researching hotspot of GIS application recently. It is one of the key problems to solve the differences among the format, structure and semantics of spatial data, and realize the organic integration of multi-data sources. This paper adopts interoperating integration schemas, and solves such problems as the accessing of heterogeneous data, retractility of integrated system, and interoperation of data and so on, by introducing GML, SVG, Metadata and Web Service technologies. Thus it offers some good information services for the users, and realizes the organic integration of distributed, heterogeneous, autonomous, massive spatial information, and in the meantime it improves in evidence the whole performance of the system by introducing the second catching technology.The main research work is as follows:(1) It deeply studies on the data behaving ability and the extending ability of application of GML, analyses the application predominance in the integrated system of multi-data sources of GML technology. According to the status quo of spatial information leaving behind, it discusses the conversion from spatial information to GML data, the parsing and the realizing methods of querying of GML document.(2) On the basis of the deep research on the map behaving ability of SVG technology, it analyses the conversion method of XSLT, and writes the conversion template of XSLT, according to the corresponding relationship between the spatial graphical element between GML and SVG. (3) It researches the working theories of Web Service and Metadata technology, and analyses the application method in the multi-data sources integrated system, thus discusses the realizing methods with which to solve such problems as data assessing and rapid position by the users.(4) It analyses the performance problem of current data integrated system, and puts forward the idea of twice caching for GML document, and then discusses such problems as the management , replacement-policy and coherence of caching module.(5) On the application demand of the city traffic management, it designs and realizes a multi-data sources integrated prototype system, which consists of application layer, data integration layer, service layer and data layer, and each layer is transferred by Web protocol, thus basically realizes the integration of heterogeneous and distributed spatial data, which has high responding performance. According to the analysis of the foundation of prototype system and caching performance, it proves the feasibility of WebGIS of multi-data sources, and offers a new integrated thought for realizing the share of spatial information and integrating large-scale data.更多还原