Tomographic SAR Reconstruction of a 4D City using TerraSAR-X data

Driven by military and civilian applications, the demand of very high resolution mapping
and accurate monitoring has increased rapidly over the recent years. Nowadays, it is
possible to create 4D models involving time variations using multiple synthetic aperture
radar (SAR) images, combined with interferometric methods. SAR has evolved to satisfy
a variety of applications for civilian and military users, for example by supporting
catastrophe management, detection of geological changes, monitoring large construction
sites or mines. With the help of SAR data obtained from the TerraSAR-X satellite, infrastructural
monitoring is made possible from a distance. The benefit of this is that
potential collapse within mines or tunnels could be prevented. Concrete degradation that
could lead to building collapse, endangering people’s lives can also be identified before
any catastrophe has the chance to occur.
Currently, Tomographic SAR (TomoSAR) is the most advanced and competent interferometric
SAR (InSAR) method in the area of urban monitoring. TomoSAR makes
monitoring in 4D possible by creating the 3D position with the motion parameters.
This thesis applies a new TomoSAR technique and method, developed by ZHU and her
colleagues, 2012 [1], on a very high resolution (VHR) spotlight data stack in the area of
Berlin. The images were taken by the TerraSAR-X satellite (Germany) over a timeframe
of 3 years. The result is a 3D point cloud of the observed area, with the velocity of linear
motion and the amplitude of periodic motion.
The result of the work that forms the basis for this thesis, is the realization of high
deformation and motion in Berlin’s infrastructure, especially around Berlin’s main station,
on bridges (” Überflieger Brücke”) and railways - often up to 10mm.