Remote sensing has the advantages of wide detection range, fast information acquisition, short period, large amount of information and less restriction by ground conditions, and can realize real-time dynamic monitoring of ground information.
Global Satellite Navigation System (GNSS) uses satellites for real-time positioning and navigation around the world. It is mainly composed of satellite constellation (space part), ground monitoring system (ground control part) and signal receiving system (user part). It can provide users with accurate three-dimensional coordinates, speed and time, and is suitable for land, ocean, aviation and aerospace, with global, all-weather, continuous and real-time characteristics. At present, global satellite navigation systems include the global positioning system (GPS) of the United States, the global satellite navigation system of Russia, the Galileo satellite navigation system of Europe and the Beidou satellite navigation system (BDS) of China.
Geographic Information System (GIS) is a computer information system for inputting, processing, storing, managing, querying, analyzing and outputting geographic data. Using the spatial query and analysis function of GIS, related data can be superimposed and analyzed according to different uses.