GIS based on the solution space/geographic coordinates for the main purpose computer system. It was founded in based on the data of data is the soul of GIS. Data into vector data and raster data. Vector data and raster data formed GIS data model. Through the data model and advanced computer technology we can draw many maps of main elements, symbols, and also can simulate the terrain, also can saying is the virtual reality technology. GIS application in many aspects, such as mapping, environmental protection, urban planning, communication, transportation etc many aspects. It's main use is the spatial analysis, spatial analysis can solve a lot of problems. Its aim is to provide a space framework -- in this system, we can use the rationalization of the earth's resources and the sustainable development of human environment management decision support.GIS is the most important data, it comes from the original map data digitization, remote sensing image, measurement data and digital material and written report. Data obtained through analysis, screening, after processing can be put in the database. What is worth mentioning, GIS data have data quality index, the index has micro and macro aspect, micro aspect it is to appoint a precision, attribute precision, logical consistency and resolution differences, macroscopic aspect is the integrity, timeliness, according to index, regional.
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