Raster Data, Raster Data Query & Advantages and Disadvantages of Raster Data (Especially for GATE-Geospatial 2022)

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Cell-based raster data sets are especially suited to representing traditional geographic phenomena that vary continuously over space such as elevation, slope, and precipitation. They can also be used to represent less traditional types of information such as population density, consumer behavior, and other demographic characteristics.

In its simplest form, a raster consists of a matrix of cells organized into rows and columns or a grid where each cell contains a value representing information, such as temperature.

Rasters are digital aerial photographs, imagery from satellite, digital satellite, digital pictures, or even scanned maps. This data structure is commonly called “raster” or “raster data structure” or “raster data model” .

This tool extracts part of a raster based on an attribute query or a location query. Location can be defined by a polygon graphics, a feature, or a raster dataset.

Rasterization

Advantages of Raster Data

  • A simple data structure - A matrix of cells with values representing a coordinate and sometimes linked to an attribute table
  • A powerful format for advanced spatial and statistical analysis
  • The ability to represent continuous surfaces and to perform surface analysis
  • The ability to uniformly store points, lines, polygons, and surfaces
  • The ability to perform fast overlays with complex datasets

Disadvantages of Raster Data

  • Volumes of graphic data
  • Raster data structure my seem undesirable because of the lack of absolute location information.
  • The cell size determines the resolution at which the data is represented.

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