MONTE-CARLO SIMULATIONS OF LARGE-SCALE ONE-DIMENSIONAL RANDOM ROUGH-SURFACE SCATTERING AT NEAR-GRAZING INCIDENCE - PENETRABLE CASE

Scattering from dielectric one-dimensional (1-D) random rough surfaces at near grazing incidence is studied for both TE and TM cases. To obt ain accurate results at incidence angles of 80 degrees-85 degrees, we use long surface lengths of up to 1000 wavelengths. Numerical results are illustrated for dielectric surfaces corresponding to soil surfaces with various moisture contents, Results indicate that TM backscatteri ng is much larger than that of TE backscattering, The ratio of TM to T E backscattering increases as a function of soil moisture and can be u sed as an indicator of soil moisture in remote sensing applications, H owever, the ratio of TM to TE backscattering is much lower than that p redicted by the small perturbation method, To facilitate computation o f scattering by such long surfaces, the previously developed banded-ma trix iteration approach/canonical grid method (BMIA/CG) has been exten ded to dielectric surfaces, The numerical algorithm consists of transl ating the nonnearfield interaction to a hat surface and the interactio n subsequently calculated by fast Fourier transform (FFT).