Health monitoring approach for transport infrastructure and bridges by satellite remote sensing Persistent Scatterers Interferometry (PSI)
Valerio Gagliardi, Andrea Benedetto, Luca Bianchini Ciampoli, Fabrizio D’Amico, Amir M. Alani, Fabio Tosti
Abstract
The satellite PSI Interferometry is a radar-based remote-sensing technique, which is capable of monitoring and measuring displacements with a high precision of the Earth’s surfaces by means of multi-temporal acquisitions. These are collected without interfering in any way with the operating conditions of the transport infrastructure as opposed to the common non-destructive survey methodologies (e.g. GPS, accelerometer, total stations). Nowadays, the use of medium ground-resolution SAR-datasets, acquired by C-Band sensors (operating at a frequency of 5.4 GHz), allow to conduct computationally affordable analyses, detecting displacements with a centimeter accuracy of the measurement. Furthermore, the use of images acquired by the new generation of high-resolution X-Band radar sensors (operating at a frequency of 9.6 GHz), allow to increase the ground-resolution and achieve a millimeter displacement-resolution This study aims at demonstrating the potential of the PSI remote-sensing technique to develop and formulate an innovative health-monitoring methodology and approach for structural assets such as bridges, using a multi-frequency satellite resolution. For this purpose, in this study C‐Band Sentinel‐1A SAR products provided by the European Space Agency (ESA), and X‐Band COSMO‐Skymed products provided by the Italian Space Agency (ASI) were acquired and processed. Furthermore, a PSI analysis was developed to monitor and detect structural displacements of a bridge of historical values. Outcomes of this investigation outlined the presence of various PS over the inspected bridge, which were proven useful to achieve a more comprehensive health monitoring and the assessment of the structural integrity of the bridge. This research paves the way for the development of a novel interpretation approach relying on the integration between remote-sensing data and non-destructive information collected on-site (e.g., GPR surveys and Laser Scanner), to improve and optimize current maintenance process of transport assets.