Height data Noordwaard 2010

Elevation model of project Noordwaard in the form of a grid with a resolution of 2 meters where the height value is included in meters. A digital height model (DHM) is a file where the height is displayed according to a regular, rectangular grid. Each cell of the grid (also called a grid cell) is given a height value. This high value is calculated from the surrounding laser points of the filtered base file. The technique used for this is a so-called “weighted average interpolation”. More information and explanations about the interpolation can be found in the manual ‘the grids of the AHN’ at www.ahn.nl. If there are no laser points near a grid cell, the cell remains empty (the cell gets a ‘nodata’ value). Important to know is that the value of a 2x2 meter grid cell is calculated from multiple laser points (the number depends on the point density of the base file). As a result, the influence of the measuring noise and outliers decreases and a slight degree of flattening occurs. For further information see quality document