The use of radar satellites for Structural Health Monitoring (SHM) purposes appears very attractive since they allow the collection of data on large areas without direct access to structures. The data collected by satellites are processed to obtain temporal histories of displacements through which the health state of a monitored system can be potentially identified.

However, several challenges are faced in using remote data for inferring structural features and carrying out consequent assessments of the health state of a structure. Furthermore, anomalies in the time histories of displacements are not necessarily due to irreversible alterations in structural behavior. Environmental phenomena, such as variations in atmospheric temperature, rains, etc., can modify the behavior of structures, without compromising their safety. The impact of these phenomena on the structural response can hinder the identification of anomalies or lead to false alarms if such alterations in structural behavior are misinterpreted as damage. This is even more true if the monitored system is a historical structure, whose uncertainties on the structural behavior are inevitably increased during aging.

The purpose of this article is to discuss the possibility of identifying structural anomalies due to seismic actions considering the impact of variations of environmental factors on the time histories of the displacements measured by satellite sensors. A study of the structural health condition of historical structures located in the city of Rome (Italy) hit by the October 2016 Central Italy earthquakes is carried out, resorting to the use of interferometric satellite data. The satellite data are acquired by COSMO-SkyMed (CSM) of the Italian Space Agency and processed by CNR IREA and consist of displacements recorded during an acquisition period between 2010 and 2019.