Mapping surface features with high resolution DEM generated from Lidar
Posted by abejorro34 on 1 December 2017 in English. Last updated on 3 December 2017.Example of use at mountain relief modified by mining and agriculture
Lidar (light radar) is a technique providing a very precise surface scanning. Airborne laser scanning generates a dense point cloud (several points per square metre) representing reflections of light ray. It contains reflections as from the vegetation as from the surface under it. Vegetation and building reflections may be filtered to get relief data only and create a digital elevation model (DEM) of relief. It is usually a raster and each pixel value represents the relief elevation. This raster may be further processed for better visualisation of relief shapes:
- Hillshade raster – grayscale 3D visualisation,
- Slope raster – colour represents the rate of change of elevation,
- Aspect raster – colour represents the downslope direction.
Surface irregularities cause by human activities are clearly recognizable in the high-resolution DEM obtained from Lidar.