WebGIS Symbol Design And Management Based-on XML And Application In Interactive Mapping

WebGIS is the result of Web technology applying GIS.At different development stages and because of different background of culture and technology as well as different development environment, traditional WebGIS have different characters and have formed their own data model, so they are difficult to carry out data share and interactive operation. The ability of XML such as accurate data expression, data model visualization and data various display provide the chance for solving the forward difficulty. In the network environment, which is based-on XML and OGC specifications, OpenGIS is the most basic approach to solve data share and interactive operation.Geographic spatial data visualization is all through an important research direction of GIS/WebGIS, whose nuclear content is map symbolic library and map symbol design and management. Workstation GIS software, desktop GIS software and traditional WebGIS software realize visualization from geographic spatial data by applying centralized symbolic library. In OpenGIS, the integrated application between OGC SLD and OGC WMS show the thought of style display separated from data content, which is advocated by OGC. The development of WebGIS based-on XML and the concept of user-oriented interactive operation make it possible and feasible for the user to design symbol and manage symbol at client-side of WebGIS in distributed environment.The paper begins with the introduction of OpenGIS and XML technology, analyzes and compares detailedly symbol design and symbol management of ArcXML, SVG and SLD, provides distributed symbolic library and researches how to organize and manage symbols by visualization as well as how to access and manage distributed symbolic library. Based-on all kinds of the functions in distributed symbolic library, designs a flow of work by which user can design symbol and manage symbol distributed symbolic library, as well as realize interactive mapping based-on WMS by combining SLD, uses Deegree WMS and its sample data to test interactive mapping, offers an idea for web mapping in web map service environment. The main fields are researched as following:The paper analyzes the characters at the aspects of symbol design, symbol organize, symbol expression, and symbol management of Point, Line, Polygon, Text about ArcXML and SLD.The paper researches distributed symbolic library, includes mainly how to define and organize symbolic library and symbols and how to access and manage distributed symbolic library.The paper designs a flow of work, in which the user readssymbolic library XML document from distributed symbolic library, manages these symbols by visualization management tool, saves all classes of symbols XML document fragment and transforms into SLD document, realizes interactive mapping by dint of integrated application between OGC SLD and OGC WMS.