Release Technology Of Spatial Information Based On MapServer

Along with the broad application of the Internet, the GIS software is becoming more supportive for the B/S mode, which is based on the C/S system structure. Based on the B/S mode, the Web GIS is used in the Internet instead of the single machine and the LAN, Recently, the fast development of the open source software provides both the medi-enterprises and the mini-enterprises with the feasible approaches to build the geographic information system, to release and share the geographic data.The AJAX mode was raised up by Jesse James Garrett in Feb 2005. Then, the Web applications based on the AJAX emerges in endlessly. Compared to the traditional Web applications system, the Web applications based on the AJAX is quite different for the users. The AJAX engine between the users and the server is introduced to design the user interface and communicate with the server, which changes the working of the internet applications under the traditional Web applications system, and reduces the difference between the Internet applications and the desktop applications.WebGIS is mainly used to release spatial information which is carried by the map. The architecture and the methods of development of MapServer are researched. This paper discusses how to use MapServer which is a kind of open-source software to build a dynamic and alternant web map. This paper analyses the application of Ajax in WebGIS, and makes a further discussion on how to improve the interactive of system by asynchronous transfer to make the client refresh in time. At last, the prototype system is designed and implemented, which is effectively, dynamically and interactively used in the web map.The key problems to be solved are as follows:Map elements are dynamically displayed by category;Design the map tile and coding;Conversion between Screen coordination and spatial coordination and the conjunction with map tile;Exchange the asynchronous data between client and server.Based on MapServer, this paper researches on the construction of WebGIS system, which gives the interactive dynamic network map's principle and method of design, and has shown the prototype system. The asynchronous transmission dynamic network map's feasibility and medium-sized enterprises were confirmed, which simply and effectively release spatial information on the Web.