Rasterlagen

Rasterlagen in geographic information systems (GIS) refers to a data layer composed of a regular grid of cells, or pixels, each cell carries a value representing a geographic attribute. Raster data contrasts with vector data, which uses points, lines, and polygons to model features. Raster layers are well suited for representing continuous phenomena such as elevation, temperature, precipitation, or satellite-derived indices. They are also used for categorical data by assigning each cell a class label.

A raster layer has a defined resolution, which determines the size of each cell in ground units, and a defined extent, which covers the geographic area. The data type of cell values (integer, floating-point) influences storage and computation. Common formats include GeoTIFF, IMG, and grid-based structures in GIS software. Operations on raster layers include resampling or reprojection when changing resolution or coordinate reference system, as well as overlay, masking, and zoning analyses. Spatial analysis often involves map algebra, focal (neighborhood) operations, and multiband rasters for combining different attributes.

Advantages include simple structure, straightforward cell-wise computation, and efficient storage for large continuous surfaces. Limitations include large data volumes at high resolutions, lack of explicit topology, and potential artifacts at cell boundaries. Rasterlagen are foundational in remote sensing, environmental modeling, and terrain analysis, frequently used in combination with vector layers to support mapping, navigation, and decision-making.