Design And Realization Of A Spatial Information Sharing Model Based On GML

With the development of GIS and network technology of computer, WebGIS arose and received a good growth. But because of the close GIS in actual existence, it is very difficult to share spatial information each other. This situation set a big obstacle in the course of GIS socialization. So it is necessary to find a new way to resolve the problem.Geography Markup Language is promulgated by OpenGIS Consortium. It's based on XML and it's a new model of spatial data. GML provides a new way for dealing with spatial information sharing in WebGIS. The paper builds a spatial information sharing model which is based on GML and uses Java technology to accomplish the model in order to improve the existing WebGIS system.The paper focused on the research about the following aspects:(1) Taking GML as the framework and combining the traditional B/S structure, the author designed a spatial information sharing model. The model emphasized the sharing of geographic information at data level, and wanted to eliminate the differences between many sources of geographic data.(2) XMLl.O and GML3.0 specification were studied to improve the existing WebGIS technology.A spatial data exchange format was put forward after researching mainstream GIS data formats and the conversion of spatial data based on GML. The design and accomplishment about GML converter were discussed in detail.(3) A JTS converter was designed after studying the open project Java Topology Suite.The JTS converter can describe the topology relationships of simple two-dimensional network (such as roads network in the city) in GML files.(4) At the client side, with the help of SVG plug-ins, the model system achieved spatial information visualization.Through the researches mensioned above, the following conclusions can be drawn:Using GML in expressing spatial data is very effective to share the spatial information;JTS converter which was based on Java Topology Suite can describe the topology relationships of two-dimensional simple network truely and effectively;Using SVG technology to achieve spatial information visualization can guarantee the map quality when mapis shrinked and enlarged.Because of limiting time, the partial design and experiment would be perfect ulteriorly.