Research On The Collaboration Plotting Strategy Based On WebGIS

With the rapid development of Internet technology and geographical information technology, it has been widely applied to all walks of society to use GIS data and services on the Internet. Based on map services published by GIS data, Collaboration plotting perform work on the computer in a two-dimensional map. It combines the Internet, the advantage and synergies character of GIS, which is a typical application of CSCW(Computer Supported Cooperative Work) technology. It allows user node distributed in different areas to execute the plotting operating on the same map.In our daily life, It’s likely to generate collaboration plotting operation of synchronization, when a certain node trigger the event of collaboration plotting for the reason of network anomalies, network transmission delay and user nodes plotting synchronous operation and other issues. When we develop collaboration plotting system, the mainly problems we meet are collaborative real-time plotting interface and node synchronization.To solve these problems,this paper makes a better use of partial-page refresh and CometD message communication mechanisms,which ensure real-time of collaboration. The use of Coordinate replacement algorithm ensures the synchronization of plotting interfact. The main content and research focus of this work are as follows:1. To research the basic theory and technology of collaboration plotting model. Firstly, this paper discusses the basic theory of Web GIS, analyze its patterns, features and advantages; and then followed with a brief overview of the third-party software products used to build WebGIS platform.2. Analysis of real-time collaboration plotting problems. It depends on a reliable and stable platform environment to carry out collaboration plotting. Using partial page updates and message mechanism based on CometD to ensure real-time of plotting information broadcast, and enhance users’ experience as a whole during collaboration plotting.3. Analysis of collaboration plotting nonsynchronization conflict. In this paper, according to the standard five-fifteen minute cut tile data as the basis for a map layer data WebGIS area. When a node plotted data in WebGIS map area,the difference of the projection format will result in synchronization when plotted broadcast content. This paper solves this problem by the use of coordinate permutation algorithm.4. Practical application. This paper realizes the encoding of algorithms and techniques in the collaboration plotting policy. Currently, co-plotting system constructed by plotting the cooperative strategy has been integrated in the high score major national special projects.