Webgls Applied Research And Development In Wide-area Surveillance System

The wide-area monitoring system has been used widely nowadays, through which can achieve the purpose of monitoring the wide distributing objects. As the information display platform of the wide-area monitoring system, WebGIS is used to display the information of objects directly and intuitively, which can avoid the tradition ways of presenting information monotonicity and abstract. So it has a great significance to study WebGIS system.Vehicle monitoring system is an important component of wide-area monitoring system. In this paper, the system of WebGIS is studied in the background of vehicle monitoring system. First of all, according to the requirements of the vehicle monitoring system, the whole architecture of WebGIS is designed as three-tier structure:Data Access Tier, Business Logic Tier and User Interface, and then the functions and technology of each tier is studied and analyzed respectively; Second, the extended relational database PostgreSQL+PostGIS is chosen by comparison with the features and storage methods of spatial data, then the management of spatial data and the applications of spatial database are designed to enhance the spatial data loading and query speed; Third, extending the functions of open-source map engine SharpMap, and re-packaging User Interface tier with ASP.NET CallBack technology, to resolve problems of limited functions and poor encapsulation of the original map engine; At last, introducing the third-party map engine Google Maps API into WebGIS system, which can achieve the effect of the satellite map by the coordination of WebGIS server and Google Map server, and vehicle location and history track display is feasibility in the satellite map.