Research On WebGIS Inter-Operability Based On GML

After the concepts about NSDI and Digital Earth putted forth, an open geographical information net ,based on Internet information platform , global geography coordinates and its relations, are coming into forth. Spatial data has became shared by the global, and it banish the limitations of space and time. Geographical information is more and more important part among national or word information flow, and Geographical information service has became one of social basic services. But there are some serious problems ,with the popularity of gis. The data sharing is an obvious example., if not solved well,it will hinder the development of gis. On the one hand, open net environment and large volume of data resource requires these data to be shared, on the other hand, the close model of data process hinders the interchange of these data. The solution to this problem is to realize data interoperation.OGC is an organization devoted to the standardization of gis, it set down a series of specification about open spatial data interoperability. GML is an specification of spatial data express, is the application in the domain of gis. It inherits all advantanges of XML, and is ideal language expressing spatial data, and is one of key technologies to realize spatial data sharing.The paper firstly summaried current problems existed in webGIS interoperability, then introduced the application of GML in gis. At the same time , the paper realized the procedure of spatial data interchange based on GML. At last the paper provide a mediare model based on GML,which improved the structure of WebGIS. The paper intended to illustrate the role of GML in WebGIS interoperability.