Forest Effects on P-Band Signals of Opportunities Based on Fast Hybrid Method of Full Wave Simulations

To quantify the forest effects on P-band radar remote sensing, this paper utilizes the fast hybrid method (FHM) combining fast multiple scattering theory (FMST) and a numerical electromagnetic solution. Considering estimation of the domain area, the required number of trees for P-band signal analysis is 121. For the efficient scattering solutions of a large number of trees, the FHM uses the triple FFT applied to the Foldy-Lax equation where two FFTs are applied to a 2-D spatial domain and one FFT to the order of cylindrical waves corresponding to translation addition theorem. This speeds up calculation of a translation addition matrix multiplied by a column vector. The accuracy of FHM is validated by FEKO using 25 trees, showing excellent agreement. Also, FHM provides faster solutions than commercial software. Using dielectric constants of winter and summer conditions, forest effects in P-band signals are validated by calculating transmissivity.