Rasterzelle

Rasterzelle is the basic unit of a raster data model used in geographic information systems and digital imagery. It represents a fixed-size area in geographic space or within an image, and it is assumed that all attributes within the cell are uniform. A raster dataset consists of a grid of Rasterzellen arranged in rows and columns; the cell size determines the spatial resolution of the data. Each Rasterzelle stores a value that encodes a measured quantity, a class label, or a category, depending on the data type. Common data types include integer, floating point, and boolean, with a designated nodata value to represent missing information.

Georeferencing links raster cells to real-world coordinates. This is typically achieved through an affine transformation that maps row and column indices to coordinates, with the cell center commonly used as the representative point for analyses. The grid alignment and cell size influence how measurements align with real features and how different rasters can be compared or combined.

Rasterzellen are central to a range of spatial analyses, including resampling when combining rasters of different resolutions, aggregation to coarser grids, and neighborhood or focal operations that compute statistics over nearby cells. Map algebra techniques operate on the values of neighboring Rasterzellen to derive new rasters.

In practice, Rasterzelle concepts apply across remote sensing, digital elevation models, climate and hydrology models, urban planning, and ecological modeling. The term highlights the geographic, grid-based nature of the data, distinguishing raster cells from pixels in purely image-centric contexts. Storage formats for rasters include GeoTIFF, NetCDF, and ASCII Grid, among others.