Quantitative parametric imaging by ultrasound computed tomography of trees under anisotropic conditions: Numerical...

A method for the reconstruction of 2D tomographic images adapted to wood was presented, aiming to perform a nondestructive evaluation of standing trees. The proposed method takes into account the orthotropy property of wood material, performing an iterative process that approximated the curved rays. A slowness function was defined for every cell and a nonlinear regression allowed the mapping of the inner elastic constants. Four numerical configurations were tested representing real cases usually found in standing tree monitoring. These specific configurations allowed this work to focus on the analysis of the effect of anisotropy on image reconstruction. The reconstructed images using the proposed method were compared with a straight-ray reconstruction method (filtered back projection algorithm), highlighting a more detailed identification and quantification of the inner state of the anisotropic structure of the trunk.