A New Approach to Relief Representation

Relief representation is a difficult problem. The surface of the Earth cannot be defined by a physical or mathematical representation but can be approximated by digital elevation models (DEM), triangular irregular networks (TIN), and contour lines. Each representation carries approximation errors. A DEM introduces the greatest errors because we assume that the surface of the Earth can be approximated to a regular grid of elevations. A TIN introduces less error than a DEM because we use an irregular network of triangles to represent the relief. Another representation is by contour lines. Contour lines describe the relief without approximation along each contour. Contour lines are the relief representation that introduces the least amount of error. In this paper we will present a new approach to relief representation using linear features. The new encoding approach is an extension of the Freeman chain code, where the regular coding grid is replaced by a circular structure.