期刊名称：ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences
印刷版ISSN：2194-9042
电子版ISSN：2194-9050
出版年度：2004
卷号：XXXV Part B2
页码：194-199
出版社：Copernicus Publications
摘要：The geo-data infrastructure (GDI) has for long been developed as a network for spatial data discovery and access. As a result spatial data, in distributed and heterogeneous databases, are readily accessible and sharable. Spatial data abundance notwithstanding, a rapidly growing segment of the geoinformation market comprises non-expert GIS users who seldom seek raw data but rather de- mand value-added information products and services of varying complexity. Increasingly, traditional geo-data infrastructures fail to fully meet the needs of emerging markets. Further, increased competition, demand for lean enterprises, pervasive e-commerce and rapid gravitation towards Internet GIS all compound to motivate the concept of a novel service-centred infrastructure that enables delivery of geo-information services and products typically beyond the capability of any single organization. Such a service-centred infrastructure has variously referred to as the Geographical Services Infrastructure (GSI). The GSI operates as a virtual enterprise comprising dynamic collaborations of many organizations partnering on the basis of core competencies and shared business objectives. The development of such an enterprise requires the design of an integrated platform that enables interoperability and inter-working of functional entities within heterogeneous environment. To facilitate access to GIS services over the Internet (Web GIS Services), mechanisms are needed to coordinate and control the execution of identified services. Workflow management services are suited for the latter set of functions while service brokers support the former. Service brokers maintain registries containing relevant service metadata to aid the discovery of required services. Workflow management services control and coordinate the execution of service chains, both intra- and inter-enterprise, negotiate and enforce adherence to quality of service specifications (service level agreements) while shielding the client from the complexities of the chaining process. The ser- vice broker and WFMS are thus central components of a GSI. The paper proposes a GSI system architecture in which the service broker and workflow management systems enable the delivery of services illustrating the interactions between these key compo- nents. An example for implementation is presented
关键词：Geo-data Infrastructure; Geo-Information Market; Geographical Services; Service Broker; Workflow Management ; Service; Quality of Services
