Distributed Network Of Interoperable Geographic Information Systems-oriented Research

With the rapid development of GIS, vast amount of heterogeneous spatial data has been produced and lots of heterogeneous GIS applications have been established. How to share the spatial information resource and realize the interoperability between the GIS applications is very urgent, and also is a challenge. Establishing an interoperable Distributed WebGIS is an effective way to resolve the problem. And GIS interoperability has been heavily emphasized even at the beginning research of distributed WebGIS. Distributed WebGIS which combines distributed computing technology and WebGIS technology, is an important research direction of GIS.This dissertation is focused on the research of distributed WebGIS and GIS interoperability. And its content includes following parts:1. Developing WebGIS with different application requirementsWebGIS is the base of distributed WebGIS development. Based on the analysis of main technology of WebGIS, this dissertation discusses the design and implementation of WebGIS system with different application requirements by using real application cases.2. Research on main technology of distributed WebGISThere are many ways to develop a distributed WebGIS. Traditional distributing object computing technology includes COM/DCOM, COBRA and J2EE/EJB. In this dissertation, distributed WebGIS development based on traditional distributing object computing technology is discussed and a corresponding architecture design is given. In the meanwhile, this dissertation further analyses the interoperability limitations of crossing platform between them.3. Research on Distributed WebGIS based on Web ServiceWeb Services, a new generation of distributing computation technology, have advantages over traditional distributing object computing technology with the properties of common data format, loosely coupled relations and strong capability of integration etc. In this dissertation, the author introduces a new method of developing a distributed WebGIS based on Web Services, and designs an architecture framework for the distributed WebGIS on the basis of common three-tier architecture of WebGIS.4. Research on spatial data model and GIS service specificationA vital purpose of developing a distributed WebGIS is to share spatial information resources and realize GIS interoperability, and spatial data standard and GIS service specification play important roles. This dissertation discusses deeply the OGM(Open Geodata Model), SFS(Simple Feature Specification), GML(GeographyiiiMarkup Language) and OWS(OpenGIS Web Services) by OGC(OpenGIS Consortium), which are the basis of spatial data interoperability and GIS service interoperability under distributing network environment. 5. Application cases of distributed WebGISIn this dissertation, two application cases are given. The first one is Spatial Information Web Service System, a distributed WebGIS based on Web Services. This application system is part of Research on Spatial Information Search Engine project. It integrates GeoBeans Map Web Service, ArcIMS Map Web Service, Place Name Web Service and Projection Transform Web Service to provide map-searching service by place name for users. The system demonstrates its capabilities of integration and interoperability crossing GIS application systems.Another one is Spatial Information Sharing and Services Platform for Digital Fujian project. In this project, the author designs and implements a WebGIS application system for distributed spatial data sharing and publishing. The system provides integrated application environment for distributed spatial data, with the capabilities of uniform management and remote processing of spatial data. It includes the following functions: loading spatial data locally and remotely, remote processing (e.g., buffer analysis)of spatial data etc.