WMS NW DHM Overview

The overview shows the current availability of Digital Height Models (DHM) in North Rhine-Westphalia. DHM is a set of digitally stored elevation values of regularly or irregularly distributed surface points that adequately represent the structure of the Earth’s surface. DHM refers to digital terrain models (DGM) and digital surface models (DOM). Common distinction is made between primary and secondary DHM. While a primary DHM contains the original readings (name L), a secondary DHM is a derived model that has a regular grid. Geobasis NRW provides different digital elevation models.As a detection method, aircraft-assisted laser scanning (ALS) is used in North Rhine-Westphalia. As a method for the large-scale acquisition of altitude information. As a result, three-dimensional point clouds are obtained by which the Earth’s surface or objects on it are described in high accuracy.The DHM is present with a measurement density of at least 1 pt/m². The DGM is largely available as a filtered, classified and reprocessed terrain model. It was refined by further processing of the acquisition data beyond the altitude classification in the course of the standard measurement point filtering and the subsequent acceptance test. In the areas not yet reprocessed, the DGM1L is only available as a filtered and classified dataset. The WMS on the availability of digital elevation models is updated weekly.