The framework of sharing and interoperation of geographic information
ZHANG Shuliang,TAO Tao,LüGuonian(Jiangsu Provincial Key Lab of Geographical Information Science, Nanjing Normal University, Nanjing 210097, China)
Geographic information is the material which is abstracted from real world. It possesses many characteristics, such as distributed, considerable, multiformatted, merchantable and sharable. With the increase of content and variety of geographic information, the requirement and difficulty of sharing are more and more obvious too. The paper summarizes current approaches and methods used in the sharing and interoperation of geographic information, which are data format translation and read directly, geographic data interoperation, sharing based on GML, grid and data grid, the Earth Science Markup Language (ESML), Multiinterface Symbol Display Technology (MSDT). In conclusion, the paper puts forward the framework of geographic information sharing and interoperation, in which data grid is the base and guarantee, interoperation specification is the core and key, MSDT or ESML and other sharing and interoperation technologies are necessary complementarities.