Researchers are using synthetic aperture radar (SAR) collected from satellites to detect structural changes in bridges. Using data derived from satellite imagery, this analysis can potentially detect subtle changes that indicate a bridge’s deterioration not visible to the naked eye.
The Morandi Bridge, near Genoa, Italy, collapsed in August of 2018, killing dozens of people. Researchers from NASA’s Jet Propulsion Laboratory compared synthetic aperture radar (SAR) measurements from several different satellites dating back to 2003 in order to measure the structural displacement of the bridge over time. This analysis let the researchers measure millimeter-size changes to the bridge. Analysis showed that as early as 2015, the deck next to where the bridge collapsed was showing signs of displacement. Researchers were also able to measure changes to the bridges structure in 2017 and 2018 that might have indicated a degradation in the bridge’s stability.
The results of the analysis are promising as a method for measuring subtle changes that could portend a hazardous deterioration of a bridge’s structure. The analysis currently can only be done for bridges that have been continuously covered by satellites collected SAR data.
Milillo, P., Giardina, G., Perissin, D., Milillo, G., Coletta, A., & Terranova, C. (2019). Pre-Collapse Space Geodetic Observations of Critical Infrastructure: The Morandi Bridge, Genoa, Italy. Remote Sensing, 11(12), 1403. https://doi.org/10.3390/rs11121403