The digital height model DHM25 is a data set representing the three-dimensional form of the earth?s surface. It was derived from the height information of the Swiss National Map 1:25'000 and 1:50'000 -for the extended perimeter.The base model contains the following elements: linear elements: vectorized contours and contours in lakes, vectorized lake perimeters, primary breaklines; dot elements: digitized spot heights and depth spot heights in lakes. The DHM25 represents the topography of the earth's surface without vegetation or built up areas.