Structural monitoring based on mt-dinsar data: an application to the “ansa del Tevere” bridge

The interest in the field of Structural Health Monitoring (SHM) has greatly increased in the last years, giving support to the management process and safety evaluation of existing structures. In particular, non-invasive structural monitoring techniques play a crucial role in the safety assessment of existing bridges. A really promising technique is represented by the multi-temporal Differential Interferometry Synthetic Aperture Radar (MT-DInSAR) applied to satellite derived data, whose potentialities are being investigated in the literature. This work follows previous studies by the same authors on the general framework for structural monitoring and assessment based on the exploitation of data from satellite acquisitions. An application to the case study of the “Ansa del Tevere” bridge in Rome is described in the paper. COSMO-SkyMed (CSK) ascending and descending datasets are exploited with different processing techniques to evaluate the displacement components along the vertical and East-West directions: the nearest neighbours approach, based on the combination of couples of points sufficiently close to be representative of the same target on the ground; the grid-subsampling approach, based on sub-sampling techniques on regular grids; the spatial interpolation approach for the definition of continuous maps of the mean displacement velocity. Finally, the different techniques useful for assessing the structural behaviour and monitoring of constructions are applied and critically discussed, highlighting the influence of the adopted hypotheses on the obtained results.