Research And Implementation Of Internet-based GIS For Interactive Services

With the advances of society, and the rapid development of technology, the application of GIS (geographic information system) platform has gone deep into many industries such as power systems, urban construction, transportation, aviation, water conservancy, etc. Due to the rapid development of Internet and GIS, their product Web GIS has come into being.In allusion to a certain area, Web GIS can realize collection, storage, processing, analysis, and display of required data in the terminal.However, there are some drawbacks in traditional Web GIS, it is worth studying how the traditional Web GIS to be improved.XML technology, MySQL database query techniques, C++ object-oriented design, PHP scripting language, and LINUX under the QT development platform are all used to implement a new Web GIS system, which integrate of collection, storage, query, share and display of geographical spatial data.The main research and innovation are as following:(1) Using a new way of query and display of spatial data-application clients are developed by QT in LINUX system, and the traditional "fat server / thin client" and "asymmetrical" mode is changed.(2) Local storage of map images which improve server efficiency. Get map images from local library firstly when necessary without request to the server. When a new area appears, clients request to the server for new map images, thus the number of request to server and the pressure of server are reduced.(3)Double-buffering splice maps method is proposed.Maps are spiced by double-buffering mechanisms in the clients to realize seamless splicing of maps efficiently.(4)Spatial data is stored as XML format, reflecting the "Cooperative" concept, and large areas are devided into small areas. Structured, scalable, flexible and other characteristics of XML are used to collect, store, manage and share data. Small areas will gathered into a whole, if necessary, and ion of small region is fused for unified management.(5)A wide range of application development elements are included in the diversity of GIS system and QT platform, and a large number of GIS functions are added to enrich the clients.