Global study shows spaceborne radar can accurately monitor bridge health

A new international study has demonstrated that satellite-based monitoring can transform the way engineers assess the condition of long-span bridges worldwide. Published in Nature Communications, the research integrates satellite observations with existing on-site monitoring systems to refine bridge risk assessments and reduce misclassification of high-risk structures by nearly one-third.

The study, led by Dominika Malinowska of TU Delft and the University of Bath, examined over 700 long-span bridges and found that less than 20% are equipped with structural health monitoring (SHM) sensors. Many bridges, especially in developing regions, rely solely on periodic visual inspections that may overlook early signs of deterioration. By incorporating satellite radar data, researchers revealed that more than 60% of the world’s bridges can be effectively monitored from space.

Using Multi-Temporal Interferometric Synthetic Aperture Radar (MT-InSAR), the study demonstrated that millimetre-scale displacements, caused by slow ground movement, subsidence, or structural deformation which can be detected remotely, offering engineers valuable data for maintenance planning.

The integration of satellite-based and on-site data enhances accuracy in determining a bridge’s structural vulnerability. This approach enables infrastructure authorities to prioritise inspections and allocate maintenance resources where they are most needed. Researchers highlighted its importance in regions such as Africa and Oceania, where ground-based sensor networks are limited but satellite coverage remains strong.

By combining the availability of SHM sensors with spaceborne monitoring, the proposed framework delivers a more reliable and cost-effective strategy for managing aging infrastructure while supporting long-term sustainability goals.