Raster Data and Vector Data

GISThe research data is geospatial data, which is the root cause of the difference from other systems. Raster Data and vector data are the most basic spatial data organization methods in geographic information systems.

Raster Data is a two-dimensional matrix that represents the data organization of spatial objects or phenomena. each matrix unit is called a cell ). each data in the grid represents the attribute data of the Ground Object or phenomenon. therefore, the raster data has obvious properties and is implicitly positioned. the vector data structure expresses the real world in the form of points, lines, and planes. It has the characteristics of obvious positioning and implicit attributes. Vector Data has the advantages of compact data structure, low redundancy, high expression precision, and good graphic display quality, which is conducive to network and retrieval and analysis. It is widely used in GIS, especially in small area (large scale) plotting. However, with the wide application of RS and data compression technology, the improvement of computer performance overcomes the disadvantages of large data volumes in raster data. Large-scale applications of raster data will take a dominant role. It is mainly based on the following advantages:

(1) With the development of RS technology and large-scale application, the use of raster data will promote the integrated development of RS and GIS. RS becomes an important data source for dynamic updates of spatial data. Remote Sensing Images are stored in a pixel-based grid structure, which greatly improves the pre-processing capability of raster data. These data can be directly generated or converted to GIS-based grid data.

(2) raster data can greatly improve the spatial and temporal data analysis capability of GIS. Raster Data is widely used in image algebra and spatial statistical analysis, which can facilitate the establishment of GIS models. The high version of ArcGIS software has outstanding performance in this aspect.

(3) 3D visualization has become a new trend for dynamic simulation of the real world. raster Data uses two-dimensional images to simulate geographical entities. Raster data can be used to increase the dimension to achieve three-dimensional visualization.

(4) with the development of Web GIS, the data structure of raster data is simple and realistic, it can be understood and used by most Program designers and users. in particular, the establishment of image sharing standards (such as GIF) facilitates the sharing of grid data in GIS. therefore, raster data is more practical in information sharing. therefore, with the development of GIS, raster data and vector data have developed to varying degrees. However, raster data is more widely and effective than vector data.