Height of coast 1999

Coastal altitude model in the form of a grid with a resolution of 5 metres where the height value is recorded in meters. Parts of the sandy coast of the Netherlands are set in height every year for the production of beach profiles for monitoring coastline. A digital height model (DHM) is a file in which the height is displayed according to a regular, rectangular grid. Each cell of the grid (also called a grid cell) gets a height value. This height is calculated from the surrounding laser points of the filtered base file. The technique used for this purpose is a so-called weighted average interpolation. More information and explanations about the interpolation can be found in the manual on 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 5x5 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 measurement noise and outliers decreases and a slight degree of flattening occurs.