Radar imagery provides solutions in measuring the deformations of the Earth surface, either produced by natural phenomena (earthquakes, subsidence), or by extensive mining, deforestation and other human activities.
In providing the needed input data, spaceborne systems are inefficient for a number of situations: the revisit time for a typical spaceborne SAR is in the order of weeks or months. Given this fact, in order to achieve the necessary number of acquisitions on the same test area (typically 15 or more images for PSI applications ) a large time span is necessary, during which the monitored event (i.e. ground deformation) can occur and not be observed. Therefore, the modern solution to applications that require very fine sampling in the time domain is given by Ground-based radar instruments. The immediate advantages of such an architecture are: cost efficiency, high precision of measurements and the possibility to correlate the measurements with spaceborne data.
TERRASIGNA developed its own technology for an X-band Ground-based Synthetic Aperture Radar (GB-SAR) that offers the capability to continuously monitor sites of limited extent (typically of a few kilometers) with high resolution (displacements at millimeter or sub-millimeter level) and sensitivity to terrain deformations. Typical applications of GB-SARs include monitoring of terrain slopes as early warning systems, land deformation monitoring, snow depth retrieval and detection of structural changes in buildings, dams, and other man-made structures.