Study Of Electromagnetic Scattering Model For Vegetation In Half Space

Some scattering electromagnetic problems in the multilayered media are analyzed using the Half-space Green's functions in this paper. The Green's functions of the electrical dipole and magnetic dipole lying in the multilayered media are given and calculated by the two level approximations discrete complex image method. So the Green's functions can be written as the closed forms.With these closed forms the value of the Green's functions can be obtained fastly and exactly.General Rayleigh-Gans approximation is used to obtain the electic field in the medium scatterers when we calculate the scattering fields of them in this paper, and the distribution of the current in the scatters can be got knowing the relative permittivity. The scattering fields of the leaves can be got easily using Half-space Green's function we have known.Finally,based on the analysis of a single leaf we study the scattering characteristics of the vegetation canopy which is modeled as discrete random medium. The location, oriented direction and size of the scatter are randomly distributed. Monte-Carlo method is used in this paper to model the vegetation canopy in order to accurately describe the geometrical and physical structure of it. Considering the absorbability and attenuation of the wave in vegetation canopy, we use Foldy's approximation to calculate the equivalent wave number of the fields propagating in the canopy. At last backscattering cross sections and bistatic scattering cross sections are calculated, and the scattering characteristics of the vegetation in half-space are given.