planimetrischen

Planimetric, or planimetral in German, describes two related concepts in mathematics and geospatial practice. Etymologically it derives from planus, meaning plane, and metrie oder metrie, relating to measurement. In a general sense planimetric denotes anything that concerns or is represented on a plane, i.e., in two dimensions, without regard to height.

In mathematics, planimetric (Planimetie or Planimetric Geometrie) refers to plane geometry. It studies properties and relations of points, lines, and figures in a single plane, including distances, angles, areas and shapes. This contrasts with stereometry or solid geometry, which deals with three-dimensional space.

In surveying, cartography and geographic information systems (GIS), planimetric data represent features in the horizontal plane. Planimetric maps or layers include two-dimensional coordinates (x and y) for features such as roads, boundaries, watercourses and buildings, while height information is omitted. Elevation data are handled separately as altimetric or vertical data (e.g., heights, contours, digital elevation models). Planimetric data are often extracted from aerial photographs, photogrammetry or LiDAR and can be stored in 2D GIS layers or as 2D projections of otherwise 3D objects.

Applications and limitations: planimetric representations are essential for cadastral planning, urban design and network analysis, where precise 2D positions matter but vertical relief is not required. For 3D modelling or terrain analysis, planimetric data are combined with vertical data to create three-dimensional models.