Ontology-based descriptions for semantic discovery and composition of geoprocessing services
The ability to process geospatial data will be a great benefit for spatial data infrastructures. This requires the ability to compose data providing services with geoprocessing services. Discovering suitable geoprocessing services is a major challenge in this endeavour. Current (keyword-based) approaches to service discovery are inherently restricted by the ambiguities of natural language, which can lead to low precision and/or recall. To alleviate these problems, we propose to use an ontology-based approach to GI service discovery, which rests on two ideas. Ontologies describing geospatial operations are used to create descriptions of requirements and service capabilities; matches between these descriptions are identified based on function subtyping. We use a running example from the geospatial domain to analyse which problems can occur in existing keyword- and ontology-based approaches and how the discovery of geoprocessing services differs from other service discovery tasks. The example is also used for illustrating the prototypical implementation of the proposed approach.
ontologies gi service discovery gi service composition spatial data infrastractures matchmaking