Burning Depth Determination in Wood with THz 3D Imaging Based on an Inverse Linear Synthetic Aperture

This paper presents the measurement of burn depth in burned wood using an inverse linear synthetic 2D aperture. A terahertz time-domain spectroscopy system with wide-bandwidth and antennas operating in divergent reflection geometry is used together with two linear stages to move a piece of burnt wood in two dimensions. This allows, in principle, the determination of the structural integrity of the burned wood and opens a new field of application for terahertz technology.