Digital elevation model Digital elevation model

Digital elevation model

A ‘digital elevation model (DEM)’ is a 3 D approximation of the surface of a terrain, created from elevation data.

A ‘digital surface model (DSM)’ is a representation of the Earth’s surface. It includes all objects, including, for example, forests and buildings.

The Digital Elevation Model over Europe (EU-DEM) that came out of the GMES RDA project is a DSM representing the first surface that is captured by the sensors. EU-DEM was produced by a consortium led by Indra. It covers the European Environment Agency’s 39 member countries and cooperating countries.

EU-DEM was edited by Intermap, while AGI (Aerogeodezijos Institutas) provided the water mask.

The dataset for EU-DEM was produced by the Copernicus programme, which is managed by the European Commission’s Directorate-General for Enterprise and Industry.

EU-DEM is a 3 D raster dataset with elevations captured at 1 arc per second postings (2.78E-4 degrees) or about every 30 metres. It is a hybrid product based on SRTM and ASTER GDEM data that are fused by a weighted averaging approach.

EU-DEM was generated as a contiguous dataset divided into 1 degree by 1 degree tiles corresponding to the SRTM naming convention.

The spatial reference system is geographic, latitude/longitude with horizontal datum ETRS89, ellipsoid GRS80 and vertical datum EVRS2000 with geoid EGG08 (EPSG code: 4258).

The vertical unit of this DSM is metres.

The tiles were then aggregated into 5°x5° tiles, which were projected to ETRS-LAEA by DG JRC (EPSG code: 3035).

Several products were also generated:

  • a colour-shaded relief image over Europe was created by the European Environment Agency using a hillshade dataset derived from the ETRS89-LAEA (EPSG code: 3035) version of EU-DEM. This dataset cannot be used for analytical purposes. There are also some known artefacts in the west of Norway.
  • a hydrography layer (streams, confluence points and watersheds)
  • a root mean square error (denoting the error derived in the quality assessment procedure).

All datasets of Version 1 are available as tiles (5x5° or 1000x1000km) and as single files. The datasets are encoded as:

  • GeoTIFF with LZW compression (tiles) or DEFLATE compression (European mosaics as single files) for the raster files
  • GDB for the Vector data sets.

The EU-DEM statistical validation documents a relatively unbiased (-0.56 metres) overall vertical accuracy of 2.9 metres RMSE, which is fully within the contractual specification of 7 m RMSE. The full report is available here.

Copyright Notice

Please refer to the European Environmental Agency (EEA) website for any specific provisions that might be applicable for this dataset.