Serena Tessitore

From ERS-1/2 to Sentinel-1: two decades of subsidence monitored through A-DInSAR techniques in the Ravenna area (Italy)

Land subsidence due to underground resources exploitation is a well-known problem that affects many cities in the world, especially the ones located along the coastal areas where the combined effect of subsidence and sea level rise increases the flooding risk. In this study, 25 years of land subsidence affecting the Municipality of Ravenna (Italy) are monitored using Advanced Differential Interferometric Synthetic Aperture Radar (A-DInSAR) techniques. In particular, the exploitation of the new Sentinel-1A SAR data allowed us to extend the monitoring period till 2016, giving a better understanding of the temporal evolution of the phenomenon in the area. Two statistical approaches are applied to fully exploit the informative potential of the A-DInSAR results in a fast and systematic way. Thanks to the applied analyses, we described the behavior of the subsidence during the monitored period along with the relationship between the occurrence of the displacement and its main driving factors.

Implementation of DInSAR methods for the monitoring of the archaeological site of Hera Lacinia in Crotone (Southern Italy)

The monitoring of cultural heritage and archeological sites affected by ground deformation is significant for their preservation and protection. The Differential Synthetic Aperture Radar interferometry is here applied to investigate the displacements occurring in the Capo Colonna area (Crotone municipality, Southern Italy), a site whose name derives from the only remaining column of the old Hera Lacinia temple, belonging to the Magna Graecia city of Kroton and dating to the 6th century BC. Processing and interpretation of SAR data has been carried out thanks to the availability of TerraSAR-X images, acquired in the time-span 2008-2010. The results obtained show the protraction of a well-known subsiding trend, connected to a mix of natural (lithostratigraphic setting, seismic activity, eustatic sea-level changes) and anthropogenic causes, the latter represented by the local on-shore and off-shore gas extraction activity. Displacement velocities up to 15 mm/yr have been identified along the satellite Line of Sight (LOS), both in the ascending and in the descending orbits. These two displacement rates have been combined to obtain the vertical component, which has been calculated in 30 mm over two years of monitoring. Moreover, the installation of 80 corner reflectors in October 2014 provided an improvement to the SAR interpretation, allowing not only to further investigate about the relationship between gas extraction and vertical motion but also to focus on the coastal erosion affecting the archeological site.

Detection of Subsidence by Radar Interferometric Data in the Seruci-Nuraxi Figus Coal Mine Area (Sardinia, Italy)

In the present work, an Advanced Differential Interferometric Synthetic Aperture Radar (DInSAR) technique has been used to measure deformations related to Seruci-Nuraxi Figus underground coal mine, located in the Carbonia-Iglesias mining district (Sardinia region, Italy). Specifically, COSMO-Skymed (CSK) data, obtained in the framework of the Third Not-ordinary Plan of Environmental Remote Sensing project by PSP-IFSAR technique, have been used to analyze the deformations occurring between 2011 and 2014 in the study area to improve the phenomenon knowledge. Availability of images acquired in ascending and descending geometries has permitted to calculate the vertical displacement component. Accordingly, a maximum subsidence of about 25 cm has been measured in the time span 2011–2014. Furthermore, time-lapsed vertical deformation profiles have also been carried out to analyze the dynamic ground-deformation development. DInSAR measurements have allowed obtaining information on the spatial and temporal development of a phenomenon, very useful to the cause-effect mechanism understanding aimed to improve the resources management.

Multitemporal synthetic aperture radar for bridges monitoring

The present work is devoted to analyze the potentiality of satellite-based techniques for structural monitoring of bridges. Specifically, the well-known case study of the cable stayed bridge across the river Garigliano and Ausente stream is presented. The available “in situ” data have been compared and integrated with satellite-based measurements (ERS, ENVISAT satellites) for the common monitoring period (1993-2004); thus, the temporal observation window has been extended until 2010 (ENVISAT satellite). DInSAR represents a consolidated tool for deformation monitoring and its application on man-made structures and infrastructures can make easier the detection of potential problems with a consequent improvement of risks management.