The Critical Technology Research And System Design Of Traffic Information System Based On WebGIS

Geographic information system is the new technology used for storage and processingspatial information, which is intergrated by computer graphics and database technology. Inrecent years, due to the huge demand in our society, the GIS application increasinglywidespread. And the rapid development of computer science and the development of GISproduced a qualitative change, which make the Internet has become the new GIS operationplatform. WebGIS changed the geography information acquisition, transmission, release,sharing and application way. WebGIS use Internet to publish geographic information on theweb, in order to operate an share geographic information. It’s an inevitable trend in thedevelopment of GIS.In the research based on the current situation and the trend of its development of WebGIS,this paper put forward the data release of WebGIS and the research on path search of neworkgeographic. The MapServer engine development technology and WebGIS related developmenttechnology are studied, including MapFile design and development, and render fixed-pointinquires, the map of coordinate transformation. And further, in this paper, the map interactivetechnology and GIS slice asynchronous network search technology is studied and optimized.Path searching is to find the optimal route by given the resource and destination on themap. It’s the shortest path search based on the edge and the node of the network. Thedifficulties in the path search of GIS is: The Geographic information is more complex; thenumber of nodes is huge; Data structure complicated; The geographical factors need toconsider various. The most widely circulated algorithm In the shortest path search is Dijkstra,which has a problem of searching too much unnecessary traverse in the path searching andspend too much time. It’s not apply to large figure network. For the defects, this paper improvethe algorithm according to the characteristics of the algorithm and network search features,and make up for the improved Dijkstra path search algorithm.On the other hand,in the traditional network model, browser need to refresh the web page in each time of interactive. The traditional model can not meet the real-time requirements ofthe WebGIS interactive response. Therefore this paper joined the map section technologyand Ajax network asynchronous interaction model, using the XmlHttpRequest object forasynchronous block loading in order to overcome the shortcoming. As a result, the WebGISpartial page refresh and replace can make up for the lack of traditional network model andachieve the goal of WebGIS real-time interactive response.Finally, we design an develop a comprehensive WebGIS network information release andmanagement module in.net platform. The systerm is based on MapServer engine andPostgreSQL+Postgis database. According the test and use of the system, it prove that thealgorithm useful and the design practical.