Rasteritietojen

Rasteritietojen, often translated as raster data or raster information, refers to a type of geospatial data that represents geographic features as a grid of cells, also known as pixels. Each cell in the grid holds a value that corresponds to a specific characteristic of the area it covers. This characteristic could be anything from elevation, temperature, land cover type, or the presence of a particular feature.

The fundamental unit of raster data is the pixel, and its spatial resolution is determined by the size of these cells on the ground. For example, a satellite image with a resolution of 30 meters means each pixel represents a 30x30 meter area on the Earth's surface. The arrangement of these pixels forms a continuous surface or an image.

Raster data is commonly used in various applications, including remote sensing, environmental modeling, image analysis, and cartography. Satellite imagery, aerial photographs, and digital elevation models (DEMs) are prime examples of raster data formats. They are particularly well-suited for representing phenomena that vary continuously across space, such as rainfall patterns or temperature gradients.

Processing raster data often involves techniques like image classification, spatial analysis, and map algebra. Its structure makes it ideal for performing calculations and analyses that operate on cell-by-cell basis, allowing for the creation of thematic maps and the identification of spatial relationships. Unlike vector data, which represents features as discrete points, lines, or polygons, raster data offers a way to depict the continuous nature of geographic phenomena.