Key Technology, Geographic Information Public Service Platform

With the acceleration of city information construction, the speed and the scale of the communication is more quickly than any other period of before. To achieve exchange, sharing and cooperation of the information among platforms, departments, industries and regions has become a primary problem on the road of information construction. High-speed network and advanced geographic information technologies are needed to solve this problem. Integrate urban information resources to overcome the problem of isolated island.The systems of public service platform of geographic information at present are mutual independence, and datas can't be shared adequately. Thus, the maintenance of systems alway need too much manpower and material. Having this as an background and aiming at information sharing, the paper puts up with three key technologies——SOA, Mashup and tiles of multi-level pyramids based on the situation of study at home and abroad about the public service platform of geographic information. Taking Kunming as an example to construct the public service platform of geographic information, we use ArcGIS Server and Silverlight4 to design the platform. At the end of the paper, the functions such as basic mapservice, spatial query, spatial analysis and Mashup and the foundation framework of the public service platform of geographic information have been achived successfully. The major content covers three aspects:(1) The paper uses SOA as supporting technology of the public service platform of geographic information and gives us the detail of the workflow about three basic components of SOA——WSDL, UDDI and SOAP.(2) By way of service interface, the paper mixes all sources of Web service using Mashup into the public service platform of geographic information. GIS functions are encapsulated and published under serveral special service standards and they can be used by other users.(3) The paper uses the techonolgy of tile map of multilevel pyramids cutting and implementing the tile map. Once the client requests tile map, the server-side only need fill current window full of the tile map. This act can reduce the wait time and provide smooth online mapservice for users.One bright spot of this paper is that Siliverlgiht4 is used to support Web applications including professional graph, audio and video. The Siliverlgiht4 offers users interface with multi-media and flysnow effects which have strengthened user experience. Another spot is that, the system of the public service platform of geographic information uses a unitive Web API, when several functional modules change, there need only little or no change to run the application program.