Metria Elevation data Grid50+

Timeliness: 1993 onwards
Delivery format: ESRI ASCII-Grid, ASCII-Tab
Resolution: 50 meters

Elevation data Grid50+ consists of a nationwide elevation model (DTM) in grid form with 50 m resolution.

The Grid50+ elevation data is based on the national elevation model in the form of a 1-meter grid. From this 1-meter grid, a 5 m grid is interpolated in raster format using the bilinear method, which in turn is interpolated to 10 m, the 10 m grid is interpolated to 20 m, which is finally interpolated to the 50 m grid. This interpolation chain means that each height value is representative of a larger area than if a 50-meter grid were produced directly from the 1-meter grid.

The Grid50+ elevation data can be used to:

• generate contour lines and to produce digital terrain models depicting the landscape in three dimensions
• perform summary calculations and analysis when presenting elevation layers and terrain shading in maps
• making gravity determinations
• geometric correction of satellite images

The product also provides valuable information for route planning. For example, by adding elevation data to the information contained in Topography 100, a more accurate route can be calculated.