Design of Chinese Internet Cryosphere Database
MA Ming-guo, CHEN Xian-zhang, LI Xin (Cold and Arid Regions Environment and Engineering Research Institute, CAS, Lanzhou Gansu 730000. China)
The Chinese cryosphere database, which has been realized. is made up of six sub-databases: snow, glacier. frozen ground. temperature. remote sensing and Geographic Information System (GIS) sub-databases. There are three main aims of the Chinese cryosphere database as follows: (1) The database could be shared and used in the world by the method published on Internet. which would advance the development of the cryosphere science. (2) The database would be consummated and standardized because of continuous query. construction. renewal. (3) The database would be provided with friendly interface to the users or explorers. There are two protocols used to translate the data. HTTP and FTP. The model of Client/ Server (C/S) is applied as the operation mode. Based on IDC programs. which is called by the CGI, query of the attribute data on the Internet was realized. The query could provide the users more information about the data including more query fields and more introduction on the data which would be useful to all the users and thus they could find their aims fast and conveniently. IDC programs provide a method to realize the joint effect between the Server and the users. An IDC includes three important parameters: data-source, template. SQL statement. By using the techniques such as VRML and Java. spatial data was promulgated on the Internet. When it connects with other geographic techniques such as GIS and remote sensing. VRML technique provides a real 3- dimensions geographic world for the users. which could be controlled and viewed from every direction. VRML files are the text description of the unreal space. which can be compiled by all the text editing system. Java is a kind of strong object-oriented language program. It could provide the method to query the image and graph data freely and dynamically. Java has an abundant group of object classes. Java's classes can be transform on the Internet and as a result it can issue the GIS data. Java still has the ability of Applet abstraction. As a kind of using program. Applet is a small, safe, active, cross platform. Finally. the services of the crysophere information could be provided to a great deal of researchers who are Working on the crysophere fields. Based on these beneficial attempts. it could be reached that there is a widely using vista for the Web technology to be used on the science of earth information. which is showed especially on the promulgation of the scientific database. This is an important basis of establishing Chinese digital cryosphere.