Remote Structural Health Monitoring of Concrete Bridge Using InSAR: A Case Study

Abstract

Structural Health Monitoring (SHM) provides real-time information about structural damage and its evolution over time, which supports decision-makers in managing structural integrity. However, traditional SHM systems, such as vibrationbased systems with accelerometers, require laborious installation and maintenance of instrumentation, including sensors, cables, and acquisition systems directly installed on the monitored structure. Recently, remote sensing through active satellites, such as new Synthetic Aperture Radar (SAR) missions, offers a promising alternative for monitoring infrastructure assets. This paper explores the use of SAR Interferometry (InSAR) processing to monitor the health of bridges. The full interferometry processing chain is based on Sentinel-1 and CosmoSKYMED synthetic aperture radar data and a combination of open-source routines from the Sentinel Application Platform (SNAP) and Stanford Method for Persistent Scatterers (StaMPS). The Permanent Scatterer Interferometry SAR (PS-InSAR) technique is used to derive displacement time histories. The applicability of this technique is evaluated on a concrete bridge located over the Oglio River in Isola Dovarese, Italy, which has GNSS receivers installed. To validate the methodology, PS-InSAR derived time histories are compared with GNSSderived data, and both techniques are used to quantify bridge displacement rates from October 2020 to August 2022.