RESEARCH ON THE SECURITY OF NATIONAL GEOSPATIAL DATA CLEARINGHOUSE BASED ON ASP

On the basis of the authors' experiences of setting up an NGDC Web site, this paper attempts to present some significant aspects about the security of NGDC based on ASP. They include data storing, database maintenance, new technical support and so on. Firstly, this paper discusses how to provide the security of data which is saved in the hosts of NGDC. The security model of "Networks-DB Server-DB-DB Object" is also presented. In Windows NT Server, Internet Information Server (i. e., IIS) is in charge of transferring message and the management of Web sites. ASP is also based on IIS. The advantages of virtual directory technique provided by IIS are emphasized.An NGDC Web site, at the Research Center of GIS in Wuhan Technical University of Surveying and Mapping is also mentioned in this paper. Because it is only an analoge used for case study, the transmission of digital spatial products is not included in the functions in this NGDC Web site. However, the management of spatial metadata is more important and some functions of metadata query are implemented in it. It is illustrated clearly in the functional diagram of the NGDC Web site.