GIS Park

With the constantly improving“Golden Shield Project”network infrastructure of Public security, an effective police force manpower allocation platform has become top priority. It will help maintain the social stability and public security, and safeguard the people’s lives and property. As well as it will improve the working efficiency of Public police office, make decision-making more scientific, and enhance the ability to deal with emergencies.WebGIS is a new technique originated from rapid development of internet technology and GIS integration. WebGIS has the features of good usability, cross-platform, scalablity and distribution of information-sharing. These features will make GIS used more and more widely. This paper has carried out systematic research on all the aspects related with WebGIS, including theory, technology implementation and application of WebGIS, and also designed and implemented a WebGIS-based police manpower allocation system.Firstly, this paper describes the basic concept and theory of WebGIS as well as its present research status and development tendency. This paper also carries out analysis and discussion on several implementation of WebGIS at present, and point out the weakness of traditional WebGIS, such as poor data reusability, and application at user end, as well as slow response speed. Combined with the features of B/S structure, this paper has explored deeply into the key technology as Ajax interoperability mode, distributed objects, spatial data engine etc. To overcome the shortcomings of traditional WebGIS, this paper proposes an Ajax-based rich internet application framework of WebGIS.Secondly, this paper focuses mainly on the areas as overall system architecture design, performance and safety design, organization of spatial data, as well as the system implementation. It firstly analyses the key points of system. To improve the system performance, this paper has abandoned the traditional web application model, designed .Net framework-based multi-tier architecture, and adopted Ajax, server load balancing, as well as map cache publishing programme to reduce the network load. According to the actual situation of practical application in network environment, this paper applied the Dijkstra algorithm to improve the operating efficiency of the system by optimizing the structure of storage and improving fast-pronged search. At the same time, to effectively resist the security threats to WebGIS, this paper proposes a role-based access control programme from view of security of network system and database.Thirdly, this paper describes a prototype of the system, including secure access to the system as well as basic functions such as maps’zoom in/out, highlighting the geography target was achieved; asynchronous interaction based on Ajax technology from view of client, server, as well as inter-communication; Meanwhile, based on business-critical needs of public security, it implements the function of police officers’resources auto choosing, real-time location monitoring, as well as the shortest path analysis etc.At the end, this paper gives the result of operation of this system, and carries out the pressure test and analysis for the realization of this application server system.