Scattering from tree branches using the Fresnel Double Scattering approximation

A Fresnel Double Scattering (FDS) method is presented in this paper to accurately and efficiently calculate the backscattering cross sections from two tree branches in the Fresnel zone of each other. The branches have a comparable size to the wavelength for L band frequencies in length and in radius. It is demonstrated that the FDS results provide a good approximation to the exact solutions where two branches are modeled as one scatterer. The FDS method can be employed to study the double scattering effects between tree branches in microwave forest scattering models and accurately model a tree with single scatter and double scatter.