GNGTS 2021 - Atti del 39° Convegno Nazionale

161 GNGTS 2021 S essione 2.1 Methods All the presented products have been obtained by processing satellite SAR data through the SARscape software (sarmap SA, Caslano, CH - https://www.sarmap.ch/ ), integrated into the ENVI environment (https://www.l3harrisgeospatial.com/Software-Technology/ENVI- SARscape). To investigate the behaviour of the Paternò landslide, two pairs of TOPSAR Sentinel-1 data (C-Band) were used, acquired on 22 nd and 28 th December 2018, both along the ascending (track 44) and descending (track 124) orbit. DInSAR technique [Massonnet and Feigl, 1998] was applied to generate the interferograms with 15 m ground resolution, allowing to obtain the Line of Sight (LoS) cumulated displacements in the six days timespan. Regarding the analysis of Pescosolido and Pisciotta DGSDs displacements, a large dataset of SAR images acquired during Sentinel-1 satellite mission has been processed applying the Small Baseline Subset (SBAS) technique [Berardino et al., 2002], one of the most adopted algorithms proposed in the context of multi-temporal methods of Differential SAR Interferometry. We exploited SAR images acquired in descending mode in the 11/01/2015 - 26/02/2020 time interval to determine themovements over time in the Pescosolido area. Instead, the surface displacement recorded at the Pisciotta landslide refers to an ascending dataset encompassing the 12/01/2015 - 23/12/2020 temporal interval. These elaborations are able to reproduce the displacement time series along the satellite LoS in the investigated periods. Therfore, it is possible to understand the displacement evolution over time and eventually detect displacement rate changes related to seismicity or the occurrence of significant damage to roads and human-made infrastructures. Preliminary results and Discussion The results of the SAR data processing are shown in Figure 2, by applying simple and advanced interferometry techniques. Figures 2A and 2B show the Paternò landslide displacements evaluated from 22 nd to 28 th December 2018 along the ascending and descending satellite orbit. The highest displacements, around 6 cm, are reached at the foot of the hill along both orbits and gradually decrease moving towards the DGSD boundaries. The similarity of displacement amplitudes and spatial extents along both satellite trajectories with different signs (negative and positive displacements indicate movements away from and towards the satellite sensor, respectively) suggest that horizontal displacements dominate the actual movement. Fig. 1 - Seismic hazard map expressed in terms of peak ground acceleration (PGA) for the Italian territory, with a 10% probability of exceedance in 50 years, together with the location of the investigated DGSDs. A) Paternò landside within Sicilia Region, B) Pescosolido DGSD inside Lazio Region, and C) Pisciotta landslide within Campania Region. The red curves identify the approximate boundary of the landslides.