Spatial Information Services Based On The Globus Toolkit 4.0

With the rapid development of computer network technologies and distributed computing technologies, geographic information systems are being migrated to popular, distributed, and web-based geospatial information services. The characteristics of diversity, dynamic, heterogeneity, massive data volume and distribution of geospatial information under Internet environment are challenging the traditional geospatial information services. Currently most researches on geospatial information services are based on Web Services, according to the specifications of geospatial information services established by OCG such as WMS, WFS, WCS. These technologies have made great progresses in the sharing and interoperability of geospatial information. But there are many unconquerable problems such as the process of the distributed massive spatial data, providing integrated and transparent services. As a result, the requirement of the digital earth stratagem will not be ultimately reached, such as real time disposal, information sharing. The appearance and development of grid computiong provide a reliable environment for the sharing and effective utilization of geospatial information resources. Grid is a software insfrastucture for resource share and cooperation running on network, and provides the environment for the integration of resources and services.In order to study and resolve the problems of geospatial information sharing, grid technology is imported into the domain of geospatial information services in this dissertation. In Chapter 1, the significance of spatial data sharing based on grid computing technology is disscussed and the latest status of scientific research about grid computing technology and its application on the aspect of spatial data sharing in the world are introduced. In Chapter 2, the technologies and specifications about geographic information sharing is introduced, mostly including Web Service, WebGIS, grid technology, OpenGIS and GridGIS. In addition, their value in the spatial data sharing is disscused. In Chapter 3, the theory of the core modules of grid middleware Golbus Toolkit4.0 is analyzed in detail. The uppermost research contents in Chapter 4 and Chapter 5, witch mostly involves the following two parts respectively:Firstly, a prototype about map service based on grid technology is devised and implemented. In this prototype, 1) the map service platform based on distributed and heterogenous environment is designed by using grid middleware Globus Toolkit 4.0; 2) OGC Web Service is encapsulated into geospatial information grid service which accomplishes the integration of map service and grid technology and implements WMS.based on OGIS and grid.Secondly, the architecture of spatial data storing and publishing based on the distributed and inhomogeneous platform is designed. The storage, transition, transfers and display of GIS data are basically accomplished. The function of WFS based on grid is implemented. In addition, the theory and method of spatial data storing in Oracle 10g is markedly clarified.The whole system is devised and implemented relying on GML and SOAP, which provides transparent mechanism of data access.