Use of Orbital Synthetic Aperture Radar Data in Monitoring Geotechnical and Transportation Infrastructure Assets

Persistent long-term monitoring of civil infrastructure such as pavements, highway embankments, and earth retaining systems is of significant interest to asset owners and stakeholders. The use of orbital synthetic aperture radar (SAR), a remote sensing technique, to assess the condition and performance of such assets has been attracting major interest from transportation agencies over the last decade. Currently, operational orbital SAR remote sensing systems have a high spatial and temporal resolution and interferometric capabilities that facilitate spatiotemporal monitoring of asset conditions along with centimeter-level deformation monitoring. This paper aims to provide a review of the use of SAR and interferometric SAR (InSAR) data in monitoring transportation/geotechnical assets. The review also sheds light on the recent explosion of the commercial SAR sector and its potential contribution to near real-time monitoring transportation assets in the near future. The basics of SAR and InSAR data and their relevance in assessing the condition of embankment slopes including a case study in Texas are presented here, along with the challenges and limitations of this technology specific to civil infrastructure. This study would benefit transportation/geotechnical academics and practitioners in understanding the advantages of using these novel remote sensing techniques as a reliable data source for asset management.