Satellite SAR Interferometry and On-Site Traditional SHM to Monitor the Post-Earthquake Behavior of the Civic Tower in L'Aquila (Abruzzo Region, Italy)

Structural Health Monitoring (SHM) represents a very powerful tool to assess the health condition of buildings. In recent years, the growing availability of high-resolution SAR satellite images has made possible the application of multi-temporal Interferometric Synthetic Aperture Radar (MT-InSAR) techniques for structural monitoring purposes, with high precision, low costs, timesaving, and the possibility to investigate wide areas. However, a comprehensive validation of the effectiveness of MT-InSAR in this application field has not been achieved yet. For this reason, in this paper a comparison between interferometric data and on-site measurement of displacements is proposed. The application case study is the Civic Tower of the city of L'Aquila (Abruzzo Region, Italy). After the seismic events that affected the area in 2009, an on-site monitoring system was installed on the tower to detect any changes in the damage pattern in the period 2010-2013. Furthermore, images acquired by COSMO-SkyMed constellation in Stripmap mode (similar to 3 m resolution) during the same period were processed by the Permanent Scatterer-InSAR (PSI) technique to estimate the deformation of the structure and the surrounding area. The obtained results indicate that both methods are consistent in the measurement of displacement trends of the building and a slight rotation/displacement of the tower was detected. Such evidence highlights both the huge potential and the limitations of using InSAR techniques for SHM.

Automated summary

Structural Health Monitoring (SHM) is a powerful tool for assessing the health condition of buildings. The application of multi-temporal Interferometric Synthetic Aperture Radar (MT-InSAR) techniques using high-resolution SAR satellite images has enabled precise and cost-effective monitoring of structures, but its effectiveness in this field has not been comprehensively validated. This paper compares interferometric data with on-site measurements of displacements to evaluate the effectiveness of MT-InSAR in monitoring a Civic Tower in L'Aquila, Italy. The results indicate that both methods are consistent in measuring displacement trends of the building, highlighting the potential and limitations of using InSAR techniques for SHM.