Research On Integration Of Geospatial Information Service And Grid

Geospatial Information Grid provides methods and environments to describe, organize, process, and distribute geospatial information resources and non-geospatial information resources by grid infrastructures. The final goal of Geospatial Information Grid is sharing and interoperability for grid resources and the core part of that is geospatial information services.The paper focuses on the theory and approach in geospatial information services and grid integration. The ultimate aim is to assimilate current Open GIS, Web Services standards to grid realm. On the basic of sharing computing, storage and other grid capabilities, geospatial services may provide all sorts of applications to users. The integration of OGC, grid and Web Services standards will provide the necessary infrastructure for developing tools, softwares, and services those work together and can be used by multiple communities. In the end, we construct a prototype system.1. Most grid resource models describe common grid objects such as computing, storage elements, which is not enough to describe geospatial data and services. We propose here an abstract definition of Geospatial Information Grid resources, and then construct an extended GLUE model calls GLUE-Ex. GLUE-Ex offers a uniform model to describe geospatial and non-geospatial grid resources and it has some advantages such as layered, .generality, extensibility and reusability.2. There are differences in OGC Web Services and classical W3C Web Services, which result in some difficulties for operating OWS in grid environment. The paper analysis's all the possible differences and prefers an OWS-Web Services compatible solution. The key techs of the program are WSDL generation and SOAP proxy service. By that users may access OWS in SOAP/WSDL approach. The solution was passed in WS-I test envirenment.3. Study on mainstream for grid structures. The key technologies of Geospatial Web Services implementation include geospatial WS-Resource, Implied Resource Pattern, Services Addressing, Resource Property Document and grid resource lifecycle. On the basis of previous OWS-Web Services compatible test, we specially illustrate the Grid WMS implementation.4. Data Service and Processing Service are the basic elements of Geospatial Service Chaining. We conclude inadequacies in current OGC Web Process Services. To solve the synchronization problem in an existing risk in computing-intensive and data-intensive applications, we design an asynchronous Broker Notification Service based on WS-Notification, which can update and monitor geospatial resource status in any moment and resolve the timeout problem effectively. 5. Service register and discovery has been an important issue for geospatial information grid. Classical Web Services framework adopts UDDI as its registry. However, it has some limits. In this paper, we present a novel service registry architecture, that is UDDI compliant and WSRF complaint and strongly supports grid resource metadata. The extension of UDDI includes UDDI inner taxonomy, UDDI data structure, UDDI APIs and UDDI deployment.6. Referring to grid Virtual Organization, we bring forward a new concept of UDDI Regisitry Pool for the distributed UDDI Registry nodes organization. The prototype provides users with single sign-on and active service. The services involved in the application include active service status acquisition, service subscription and notification, and service registration with QoS information which can promote frendliness, reliability and stability of geospatial grid UDDI Registry.