|Paper title||PS-toolbox: the post-processing of InSAR data for the characterization of surface displacement patterns|
|Form of presentation||Poster|
InSAR (Interferometric Synthetic Aperture Radar) is widely acknowledged as one of the most powerful remote sensing tools for measuring ground displacements over large areas. The most common multi-temporal technique is the Persistent Scatterer interferometry (PS-InSAR), which permits the retrieving of spatial and temporal deformations in landslide-prone slopes. Since PS-InSAR is based on the analysis of targets with strong stability over time in terms of reflectivity, anthropic areas affected by landslides are designed as optimal test sites for assessing displacements with millimetric precision.
Depending on the landslide kinematics and style of activity, however, differential surface movements within the landslide area or different displacement trends in the analysed time interval, may not be highlighted without further processing.
To better discriminate the internal segmentation of complex landslides or differential movements of landslide systems, a specific toolbox for the post-processing of interferometric data is proposed. The PStoolbox was developed by NHAZCA S.r.l. as a standalone software and, for the simplicity of usage, a set of plugins were designed for the open-source software QGIS with the main purpose of guiding the user in interpreting ground deformation processes. These characteristics make the PStoolbox an effective Software not only for end-users who need to understand and inspect what kind of information the interferometric data contains, but also for technicians to evaluate the results of interferometric analyses and to better understand, validate and take full advantage of the data.
To date, the toolbox includes several modules that allow to: 1) highlight the variations over the displacement trend over time (Trend Change Detection tool – TDC); 2) plot the time series of displacement for one or more selected measure points (PS time series tool); 3) calculate the smoothed data over the displacement values (Filtering tool); 4) plot the velocity or displacement values along a linear section containing the selected measure points (Interferometric section tool); 5) calculate the vectorial decomposition of the persistent scatters, starting from the data results in ascending and descending orbital geometries (PS decomp tool).
InSAR post-processed data permit the evaluation of subtle displacement patterns in terms of spatial and temporal variations, which is essential not only for the characterization of every deformation process but also for planning purposes and in a risk-mitigation perspective.