A digital elevation model is a digital representation of ground surface topography or terrain, derived using two remote sensing techniques at differing resolutions.
Fugro NPA are highly experienced in the production and supply of Digital Elevation Models (DEMs) from a variety of sources including those generated from interferometric radar techniques, such as SRTM and from Optical images acquired from different angles taken from the same pass of an earth observation satellite (such as the HRS instrument of SPOT-5 and ASTER 3B sensor). The new generation of very high resolution optical satellite sensors have the capability of generating accurate Digital Elevation Models with or without ground control.
Fugro NPA provide free independent advice on the optimum elevation product to meet a client's specification and are happy to discuss the variety of options available in more detail.
| Source | Resolution | Horizontal Accuracy (relative) |
Vertical Accuracy (relative)
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| SRTM | 3 arc seconds (90 m) | 30 m | 10-15 m (terrain dependent) |
| SPOT HRS DEM | 20-30 m | 15 m | 10-30 m (without GCPs) |
| ASTER DEM | 30 m | 30 m | 15-30 m |
| Worldview 1 & 2 | 1 m | <1 m | ~1m (with GCPs, terrain dependent) |
| GeoEye-1 | 1 m | <1 m | ~1m (with GCPs, terrain dependent) |
| LiDAR | 1 m | 0.5 m | 0.15 m-0.25 m |
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