3D Measurements and Remote Sensing

With its scientific and technical skills in the acquisition, processing and interpretation of LiDAR and photogrammetric point clouds, ground-based and spaceborne InSAR data, and satellite image analysis, Terranum has acquired unique expertise for 3D surveys and remote sensing of natural processes, with a particular focus on:

  • 3D modelling of the topography and infrastructure
  • Monitoring landslide displacements and ground deformations
  • Monitoring the deformation of galleries and other cavities
  • Deformation measurements on man-made infrastructure
  • Terrestrial and satellite radar interferometry (InSAR)
  • Optical and multispectral satellite imaging
  • Structural geology analysis on 3D data
  • Detection and quantification of rockfalls or erosion

In detail

3D surveying and modelling of topography and human infrastructure

Terranum carries out the entire chain of 3D surveys of the topography or human infrastructures, from the acquisition of 3D data to the processing of point clouds (cleaning, alignment, georeferencing) and ultimately to 3D modelling. For these 3D surveys, Terranum offers acquisitions using LiDAR (laser scanner) or photogrammetry on land (fixed position), on vehicles (boat, car, train or helicopter) or by drone. These 3D data can then be combined to track displacement or deformation.

Multi-temporal analysis of 3D measurements for monitoring displacement and deformation

Terranum has strong experience in monitoring the displacement of landslides or rock instabilities using multi-temporal analysis of 3D measurements. This technique enables centimetric to pluri-metric displacements to be mapped and quantified over the entire active area, providing complementary or preliminary information for in-situ displacement measurements. This multi-temporal analysis of 3D measurements can also be used to locate and quantify rockfalls in cliffs, erosion zones along a river or volumes extracted in quarries. The deformation of man-made infrastructure (buildings, bridges, tunnels, caverns, dams, etc.) can also be measured using this technique.

Ground motion mapping using radar interferometry (InSAR)

With the support of its network of scientific and operational partners for InSAR analyses, either on a regional scale using spaceborne InSAR (radar interferometry in C, L or X bands) or on a local scale using ground-based InSAR, Terranum produces and interprets InSAR analyses to map ground deformation on a regional scale (inventory of active landslides) or to continuously monitor the displacement rates of a landslide or a rock instability.

Change mapping using optical and multispectral satellite imagery

Terranum interprets optical and multispectral satellite data, in particular for landslide mapping after a major disaster, but also for monitoring long-term changes in the canopy, ground cover, soil moisture or agricultural practices.