Publishing And Retrieval Technique Practice Of Digital Map Resource On Web Services

With the rapid development of computer and information technology, the contents andmethods of traditional map service have undergone tremendous changes. Internet-based digitalresources have changed the manner of the traditional map inquiries and borrowing. As the mapis a pervasive feature in our lives, and the map is an important part of our lives, the traditionalmap application is facing new challenges. One important issue noted here is that because themap content is limited to the requirements for application, map data acquisition is a highlycomplex technology, existing map data is stored in the closed system under the distributedenvironment. As for the description on map contents and characteristics, namely metadata, theyare diverse from each other. This creates the phenomenon of isolated information. Therefore, theusers will spend more time and energy searching map, and the precision ratio and recall ration isnot efficient. Web Services technology characterized for its openness, encapsulation and loosecoupling provides a feasible solution for mutual inspection of spatial metadata database. Byemploying the Web Services technology into the spatial metadata interoperability, the thesisproposes the digital map resources retrieval model convenient for network discovery, designs aprototype system, verifies the feasibility of the model as well as provides a new solution torealizing geospatial metadata publishing, sharing and interoperability. The research contents andinnovations are as follows.1. To analyze the present situation of research on information retrieval in digital mapresource, the spatial metadata and retrieval protocol are proposed to discuss the issues onmetadata standard, system stability, search time and retrieval protocol etc. caused byinteroperability of digital map resources.2. To study the definition and criterion of spatial metadata, analyze the characteristics ofChina sustainable development information sharing of metadata standards, and design thespatial metadata conceptual model suitable for spatial metadata interoperability based on theanalyses.3. To study the Web Services protocol specification, the system structure and the work flow,analyze the characteristics of the model unified retrieval of traditional heterogeneous dataresources, propose a digital map resource unified retrieval service model and design the interfacespecification, parameter format and key algorithm.4. To discuss the system structure of digital map resources retrieval system based on WebServices, focus on designing the system architecture, function modules and workflow, and thenresource publishing and retrieval system of digital map based on Web Services is put forward.The whole system adopts hierarchical architecture, and communicates by the way of interface between layer and layer. It is easy to maintain and extend for the loose coupling betweenmodules.