A Rule-Based Description Framework for the Composition of Geographic Information Services

SDIs offer access to a wealth of distributed data sources through standardised service interfaces. Recently, also geoprocessing capabilities are offered as services in SDIs. Combining data sources and processing services in service chains enable the generation of information that is tailored to the users needs. In this paper, we present a rule-based description framework and an associated discovery and composition method that helps service developers to create such service chains from existing services. The goal of the description framework is to describe services at a conceptual level rather than closely mirroring specific implementation details. It consists of a simple top-level ontology as well as a domain ontology, which provide the basic vocabulary for creating descriptions of both services and the information the service chain is to produce as a result. The composition method uses these descriptions to discover appropriate services and compose them into a service chain that can produce the required information. The method is illustrated using an example from the domain of risk management.