ARTICLES
ZHANG Hong, FENG Jiangfan, LV Guonian, TENG Xuewei
.
2007, 9(2):
37-42.
Geographical Information Systems(GIS) are characterised by the ability to integrate geospatial data from a wide variety of sources.World Wide Web Geographical Information System(WebGIS) is the combination of Internet/Web technologies and Geographical Information System,it makes the Web publishing and sharing of geospatial information in the whole world possible and has exerted great influence on the national economic development and our everyday life.In the application of WebGIS,how to transfer efficiently the geospatial information,such as the user's spatial query submits and the result data from GIS database,through the network is a key factor to determine the capability of the system.This paper firstly analyses the problem existed in WebGIS,and then introduces the Rich Internet Applications,in short RIA,which is a brand-new Web application solution.Considering the trait of RIA,the thought for constructing WebGIS based on RIA is presented,and three key techniques adopted in RIA based WebGIS are summarized and analyzed.After that,this paper describes the framework of WebGIS based on RIA,consisting of five layers:client layer,presentation layer,business layer,integration layer and resource layer.In the design,the realization of client,server and protocol are discussed in detail.Finally,the thought given in this paper is proved feasible and effective with an experimental system,in addition,some future work in WebGIS based on RIA,such as security,interoperability are indicated and simply explored.The authors believe that with more research on WebGIS based on RIA,RIA will play greater role in publishing geospatial information,furthermore,the geospatial information web sharing will become easier.