Mapping the buildings stability at urban extent based on MT-InSAR and 3D rigid motion reconstruction method

The recent and planned launch of high-resolution and short revisit time Synthetic Aperture Radar (SAR) satellite missions, along with the use of advanced multi-temporal interferometric techniques, has opened up new possibilities in the field of structure and infrastructure monitoring. The cited techniques are capable of providing displacement time series of stable targets at the ground with millimetre accuracy. They are particularly relevant for preventive conservation, maintenance, and health assessment of existing built heritage.A method for reconstructing the 3D rigid motion of isolated buildings from a dual-orbit set of SAR data has recently been proposed by the authors. In that work, the assessment of the significance of the computed motion components has received particular attention due to the low entity of displacement that could potentially affect the buildings. The method was tested on COSMO-SkyMed SAR data processed using an open-source procedure. The results indicate that it is possible to detect displacements in the order of a few mm/yr and rotations in the order of mrad/yr with corresponding uncertainties that are one order of magnitude smaller than the associated parameters.This work combines the proposed structural investigation method with a Geographic Information System (GIS) dataset to develop a methodology for assessing building stability at an urban extent. GIS layers were used to define the spatial relation between scatterer locations and building shape, detecting targets belonging to buildings and retrieving the precise heights of the scatterers. The 3D rigid motion analysis was conducted for all individual buildings in the area with relevant uncertainties assessment. The workflow is able to map the potential stability issues of single buildings, at urban extent, as starting point for further investigation.The methodology has been tested on the city of Modena (Italy) and GIS layers representing the classification of building stability is presented.Funding: The methodology adopted in the present research was partially developed in the frame of the Progetti di Rilevante Interesse Nazionale (PRIN) 2022 DAMAGE “Damage Analysis and Monitoring of Ancient structures interacting with Geotechnical Excavations”, contract E53D23002550006.