Design And Practice On The Registry Center Of Geographical Information Services

With the characteristic of loose-coupling, distributed, platform-independent and dynamic on-demand integration, GIServices (Geographical information services) has been one of the major development trends and hotspot of GIS now. A great number of Rewarding research and applications supported by GIS software companies and open-source organizations has resulted in the continuous development in theories and technologies, as well as the rising of a considerable variety of GIServices. In the face with constantly enrichment of GIServices, how to make providers more competitive by their services and to help users search demanded services more precisely has been the bottleneck of restricting GIServices from developing. Therefore, after analyzing the current research situation and existing issues of UDDI and CSW which are on behalf of GISRC, the establishment target and requirement of GISRC and an open, smart mechanism for the registration and discovery of GIServices is studied and realized for the sake of the maximal sharing and interoperability of GIServices.First, the basic contents of GISRC are introduced, from the perspective of related theory and technology architecture of Web Services, the concept, framework and taxonomic principle of GIServices are set forth, the registration and discovery technology based on UDDI and OGC CSW is compared and analyzed, the concept of managing QoS (quality of service) and the method of subscribing and recommending service are presented.Second, based on the framework of GIServices, the interoperation between GISRC and GIServices providers and users is analyzed and the architecture of GISRC is build considering the QoS and service security factors. An intact category database is designed for registering GIServices and supporting the dynamic extending of taxonomic system. After that, a schema is contrived for storing metadata details of data-service, processing-service and user information of GISRC. Moreover, the logic structure of GISRC function module such as category management, registration and discovery of GIServices are designed and a security mechanism for GISRC platform is provided.Next, obtaining and parsing capabilities documents, invoking test and registration of several kinds of GIServices are studied. A united RIM coding of registering services'metadata is adopted and a QoS evaluation mode is proposed by menas of setting the weight of each QoS metric. Furthermore, In order to boost the efficiency and quality of service discovery in GISRC, GIServices discovery method such as based on keywords, data attributes, processing attributes and QoS confines, evaluation and feedback by users, and GIServices subscription and dispensation are studied and realized. The remote interface of GIServices registration and discovery based on SOAP and CSW is provided for sake of the sharing and interoperation between GISRC and other GIS application resources.Finally, a GISRC portal is experimented to validate the theories and methods proposed. Moreover, providers-oriented and consumers-oriented GISRC clients are established for the integration, sharing and interoperation between GISRC portal and other GIS or GIServices applications.