The principal component analysis could substitu te a small number comprehensive variable for original multidimensional variable and obviously simplify data structure in the precondition of minimizing loss of original data information.

A dependable for earth-air missile weapon system designing already set data information analysts calculate way has been that realm inside very tough problem.

Security and encryption technique of information data;

The encryption algorithms of information data included public key encryp- tion algorithm,symmetry secret key encryption algorithm DES transforms changing data position algorithm of data encrypfion,and electronic signature of information data package.

A great deal of information data must be inputted in space grid structural calculation.

Extraction of hydrological information from digital elevation model with ArcGis 9.0;

From 2006, new standard for hydrological information code has been used all over the country, water regime information transmission system developed by Huaihe Water Resources Commission has been popularized to encode and transmit hydrological information.

Taking hydrological information inquiry system in Fujian province as examples, the construction of hydrological information inquiry system on the basis of Web GIS is discussed.

Study on hydrology information distribution system which build on MapXtreme;

System of the Hydrology Information Remote Collection Based on GIS and GSM;