Research On Spatial Information Service Discovery Methods Based On Ontology

With the development of network technology, spatial information technology has changed from spatial information system to spatial information service. The expansion of the service object from professional users to public. User is not only the user but also the provider of spatial information service. Users publish and share all kinds of spatial information services on the Internet, It led to a rapid increase in the number of spatial information services. In the face of massive service resources, how to quickly, efficiently and accurately find their own services or to meet the needs of their own services has become an urgent problem to be solved. This paper mainly focuses on the description and discovery of spatial information services, the main contents include:(1) Spatial information service description model based on ontologyEstablishment of spatial information service description model is the basis for service discovery and service composition. Firstly, introduce and summary the theories and methods of spatial information service description. Faced with the problem that the traditional methods can't describe spatial information service completely, construct a spatial information application ontology by Protégé tool, and describe service information by OWL-S description language. Expanded the quality of service elements, laid necessary foundation for the service discovery process.(2) Service discovery strategy based on description modelAccording to the established spatial information service description model, a new three phase space information service discovery matching algorithm is proposed. The algorithm divides the discovery process into three stages. The first stage is to match the basic description information of the service; The second stage is to match executive information of the service; The third stage is to match quality information of the service. Finally, the matching results are sorted according to the spatial information service evaluation method to get the best results. The experiments show that this new algorithm can effectively improve the precision and recall of the service discovery.(3) Build spatial information service composition and sharing platform based on Cloud GIS platformBy using of a wide range of GIS cloud platform, to build a spatial information service through a combination of GIS cloud platform sharing system based on Arc GIS. The model of remote sensing image change detection will share in GIS cloud platform in the form of service, that users can quickly detect remote sensing image in any tine.