China is a developing country with a large population, limited land resources and frequent natural disasters. The problem of eating more than one billion people has always been important. After twenty years of rapid development, the contradiction between resources and the environment has become increasingly prominent. 98 years of floods, the Yellow River cut off, reduced arable land, desertification intensified, has aroused widespread concern in the community. We must take effective measures, from the macroscopic angle to strengthen monitoring and protection of land resources and water resources, especially to strengthen the natural disaster monitoring and forecasting, flood disaster prevention, avoid detours through the third world countries and some developed countries in the process of development.
Integration of the ground "three S": on-board, shipborne positioning navigation and positioning, tracking, measuring and other real-time operations on ground targets. Four, the application of digital earth in human contact with 80% of the information is related to geographical location and spatial distribution, geospatial information is the goods and vehicles on the information superhighway. Digital earth not only includes the earth's high-resolution satellite images, including digital map, as well as economic, social and demographic information, its application as vice president Gore mentioned in the report are sometimes restricted, because our imagination in other words, the application of digital earth is largely beyond our imagination. Can be optimistic that first Century, the digital earth will enter thousands of households and businesses. Here we can only make some realistic applications of our understanding. 1, the digital earth on global change and sustainable development of society and the role of global change and sustainable development of the society has become an important issue in today's world of concern, said the digital earth provides very favourable conditions for our study on this problem. The use of digital earth in computers can be used to simulate and simulate the processes, laws, impacts, and Countermeasures of global change, thereby enhancing human ability to cope with global change. Digital earth can be widely applied to the monitoring of global climate change, sea level change, desertification, ecological and environmental change, land use change. At the same time, the use of digital earth, can also carry out a comprehensive analysis and prediction, many problems on the sustainable development of society such as natural resources and economic development, population growth and social development, disaster prediction and prevention.
Three S integration technology "three S" integration refers to the above three kinds of ground observation, new technology and other related technologies organically integrated. The integration mentioned here is a Chinese translation of English Integration. It refers to an organic combination of online connections, real-time processing and the integrity of the system. The integration of GPS, RS, and GIS can be implemented at different technical levels. The "three S" integration includes an empty base, three S integration, and a ground three S integration. Air based "three S": integrated air ground positioning mode of direct observation, the main purpose is to ground control points (or a small amount of ground control points) under the condition of realization of aerospace remote sensing information directly to the positioning, reconnaissance, guidance and measurement etc..
