Keeping an eye on the health of older buildings is especially important in earthquake-prone areas—but traditional structural health monitoring (SHM) methods are often too expensive for most private property owners. This study looks into a more cost-effective and scalable alternative: using satellite radar technology, specifically Tomo-PSInSAR, to monitor building conditions across a whole city.
We focused on the Taipei Basin and used TerraSAR-X/TanDEM-X satellite data to develop a method that can detect building settlement and tilting over time. Out of all the buildings analyzed, about 11.6% were suitable for this type of monitoring, and 10.8% of those showed signs of unusual movement. Some buildings were sinking as much as 14 mm per year or tilting at a rate of 1/760 per year.
When we looked at buildings included in urban renewal projects, 9.4% met the criteria for SHM, and 11.9% of those showed deformation issues. Factors like building age and soil type helped explain some of the patterns, but not all. Interestingly, buildings that are 30 to 50 years old had more problems, possibly due to poor construction practices or materials—like the use of sea sand in concrete.
We also identified a few technical challenges: not enough reliable radar reflection points on some buildings, uneven data coverage, missing or inaccurate building outlines, and lack of information on building ages. The good news? These issues can be tackled by using satellite data from different angles, collecting more frequent images, and working more closely with government agencies.
Significant difference in 3D positioning of scatterers between Tomo-PSInSAR and traditional PSInSAR
a, b: Example of settlement analysis for a single building. c-d: Example of tilt analysis for a single building.
More information:
https://www.tandfonline.com/doi/full/10.1080/15481603.2025.2482329
