A New Model for Scattering From Tree Canopies Based on Physical Optics and Multiple Scattering Theory

This paper presents a new model for scattering from tree canopies based on a modified physical optics approach. In this way, propagation through a canopy is accounted for by respecting the complex propagation constant, which can be obtained either by the multiple scattering theory (MST) or approximated based on the canopy specific attenuation. Unlike the case when MST is applied directly, the proposed approach offers significant benefits, including a straightforward software implementation, feasible computation times for high frequencies and electrically large canopies, and, most importantly, near-field calculations in regions close to a canopy. The new model is first tested against MST using two artificial single-tree scenarios at 2 and 10 GHz. Then, experimental data at 2 GHz obtained with the use of a remote controlled airship for an actual single-tree scenario are utilized as well. In this way, the model is thoroughly validated and its advantages over MST are presented in detail.