Full polarimetric UWB GB-SAR for damage assessment of wooden building structures

A full polarimetric ground-based SAR system for subsurface damage assessment of wooden building structures has been developed. The system is based on a 4-channel VNA connected to a polarimetric antenna array. The array elements consist of 4 newly developed circular polarization cavity-backed spiral antennas, which have very good wideband characteristics and excellent polarimetric performance. By 2 dimensional scanning the system can achieve polarimetric 3D imaging with super high-resolution of 1 cm in x-/y-direction and 2 cm in z-direction. Using the polarimetric phase information, deformations of internal wooden structures like beams and bars with inclination angles <;1 deg. can be detected, which is not possible with any other non-destructive testing technique.