Using radar satellite images, displacements can theoretically be determined down to the millimeter level by measuring phase differences between successive images. This is done using an INSAR analysis. The project aims to track bridge displacements using such an analysis.

The aim of the project is to determine whether INSAR can be used in the daily management of bridges and to investigate which type of satellites and analysis are best suited for this purpose. A second objective of this innovation is to detect problems faster and deploy topographic measurements more efficiently on bridges that may pose a risk.

Among other things, the following research questions are being investigated:

• On which bridges can different techniques be applied? What is the influence of the type of bridge, the orientation of the bridge, the presence of trees, buildings, water in the immediate vicinity....
• Under what conditions can different techniques be applied? What about presence of traffic/ influence of weather conditions ...?
• Is it possible to automatically divide into a period before and a period after works on a bridge deck? How well can points on the bridge be located
• Is it possible to draw longitudinal profiles in the longitudinal and transverse direction of the bridge, indicating the location of supports and spans?
• Is it possible to detect local anomalies? What accuracy is achievable? Which resolution is optimal, taking into account all aspects (satellite return frequency, bridge dimensions,...)?
• What is the minimum number of images required for each possible technique to achieve a good result? Does this depend on the resolution of the image?
• Is it possible to link multiple images together if all of Flanders is covered with multiple image sets?
• What software options are available to visualize the data? Is a link with the management tool of the Flemish government possible?