Digital Mapping of Buildings via Satellite

Buildings can experience slight shifts in their position over the years due to external influences. These movements may cause visible damage inside and outside the structure. Satellite surveying can detect such changes, including those that have occurred in the past.

As part of a warranty contract, SPIE was responsible for monitoring structural integrity. After two new buildings were commissioned, noticeable cracks appeared in the walls during the warranty period. To document the damage, a traditional survey was carried out in one of the buildings as part of evidence preservation.

During a digital lunch session, SAR interferometry was introduced — a technology that precisely measures ground movement by comparing radar images taken over time. This sparked a pilot project to survey the entire property. The results not only confirmed the damage but also pinpointed the exact areas of the building experiencing the most severe cracking.

This new method enables the analysis of larger areas, including entire buildings, while also accounting for area-wide changes such as ground subsidence. Building damage can appear years after construction, for example due to subway construction, significant groundwater fluctuations, or new developments on neighboring properties. In such cases, measurement data from past monitoring efforts can serve as a valuable reference.

The use of corner reflectors—three mutually perpendicular surfaces—will allow even more precise measurement points in the future. These reflectors improve signal reflection back to the receiver, significantly enhancing measurement accuracy. As a result, reliable data can be provided to support structural safety assessments of buildings.