Guidance: the processing of spatial data is the core function of GIS, the data in GIS usually describes three parts of information: spatial information (location, spatial relationship, etc.), non-spatial attribute information, time information. According to its measurement scale, the data can be divided into four types: fixed name, fixed ratio, interval, and ratio. Due to various reasons, there are quality problems in GIS data, understanding the quality of data is conducive to the correct use of data and avoiding the situation of “Garbage In, Garbage Out”. Data quality can be described by metadata, in a nutshell, metadata is a description of data, metadata helps data sharing and efficient use as GIS applications continue to evolve and spatial data grows.
This chapter describes the above.