Extension of the dRET Model to Forests of Thin Cylinders

This paper presents a feasibility study on extending the applicability of the discrete radiative energy transfer (dRET) model to the trunk layer of raised canopy forests. The framework herein presented, proposes a method to predict the scattered signal inside and around a formation of cylinders (mimicking thin tree trunks), which is based on the prior knowledge of the cylinder 2-D reradiation pattern as input parameters to the dRET model. The characterization and modeling of the cylinder 2-D reradiation patterns were performed in an anechoic chamber, so that frequency-dependent effects could be evaluated. The assessment of the proposed method was performed against measurements within a formation of both metallic and dielectric cylinders mimicking thin tree trunks, at micro- and millimeter-wave frequencies, i.e., 9.4, 18.8, and 37.6 GHz.