TECHNIQUES
The extraction of useful information from optical imaging and radar earth observation satellites is at the core of ALTAMIRA INFORMATION knowledge.
Our mapping products are created from Synthetic Aperture Radar images (SAR) currently provided by Envisat, ERS 1&2, Radarsat, TerraSAR-X or Alos satellites. They may be merged with satellite optical imagery or aerial photography, thanks to the high precision and accuracy in the geocoding of our mapping products.
To measure ground motion over time or assess the topography, phase values of radar images are compared thanks to the Synthetic Aperture Radar Interferometry (InSAR) technique.
Depending on the quantity of available radar images and the required precision, different InSAR techniques are applied by ALTAMIRA INFORMATION: Classical Differential InSAR, Advanced Differential InSAR, InSAR Stable Point Network and InSAR Stable Point Network with Artificial Corner Reflectors.
Our mapping products are created from Synthetic Aperture Radar images (SAR) currently provided by Envisat, ERS 1&2, Radarsat, TerraSAR-X or Alos satellites. They may be merged with satellite optical imagery or aerial photography, thanks to the high precision and accuracy in the geocoding of our mapping products.
To measure ground motion over time or assess the topography, phase values of radar images are compared thanks to the Synthetic Aperture Radar Interferometry (InSAR) technique.
Depending on the quantity of available radar images and the required precision, different InSAR techniques are applied by ALTAMIRA INFORMATION: Classical Differential InSAR, Advanced Differential InSAR, InSAR Stable Point Network and InSAR Stable Point Network with Artificial Corner Reflectors.
 |
Classical Differential InSAR
Basic ground deformation map with only two SAR images. The quantity of ground movement that has occurred between two dates is usually presented in colour fringes, each fringe being a change of 2.8 cm (for C-band interferogram). Displacement precision: 1 cm locally, more than 3 cm over a large area. |
 |
Advanced Differential InSAR
More reliable than classical differential InSAR since a small set of interferograms is used and atmospheric effects are compensated. The ground motion rate is given for each reliable pixel over a given period of time, shown in coded colours. Displacement precision: 2 mm/year. |
 |
InSAR Stable Point Network (SPN)
High-precision ground deformation maps and ground motion time series for selected points (reliable natural radar reflectors) using Altamira Information's own in-house PSI software Stable Point Network (SPN). Better precision due to higher quantity of images. Displacement precision: 1 mm/year. |
 |
InSAR SPN with Artificial Corner Reflectors (ACR's)
Aluminium reflectors are installed to guarantee measurements points on the exact required site in areas without sufficient natural measurement points. Ground movement is indicated in ground motion time series for each artificial corner reflector. Displacement precision: 1 mm/year. |
 |
Mapping Techniques (SAR)
Digital Elevation Models, structural images and wind maps can be generated from radar images using different mapping techniques. |
|
|
|
