Small Roughness Of The Surface Scattering Of The Top Of The Object

The scattering of random surface is an important branch in the field of electromagnetic scattering and has much potency of practical applications in many subjects. Research related to random surface scattering includes modeling of random surface, scattering properties of surface and objects, multi-scattering, diffuse scattering, etc. Both analytical method and numerical method can solve problems of random surface scattering.If the random surface is treated as a sample in a sample space, the scattering wave field is a functional of the random surface. The scattering wave field induced by the Gaussian random surface is a stochastic functional which follow the statistics of Gaussian distribution. The advantage of functional method is that the mathematic description of the random scattering field already involves the multi-scattering. Thus, the statistics properties of the wave field can be gained analytically and the multi-scattering polynomial can be analyzed like perturbation method.The scattering of waves from an object above a one-dimensional and two-dimensional random rough surface with slight roughness is studied, using the stochastic functional approach. The stochastic Green function for a slightly rough surface with the Dirichlet or Neumann boundary conditions, which enable us to incorporate the interaction between the object and the rough surface, and can greatly simplify the analysis, was analytically derived. As an example, the angular distributions of incoherent scattering for a circular cylinder and a sphere above a slightly rough surface with the Dirichlet or Neumann boundary conditions have been calculated. The numerical results show that the presence of an object in the front of a slightly rough surface can dramatically enhance the backscattering peak effect, especially for the Neumann case where the effect is attributed to the participation of an unstable surface wave propagating along the rough surface into the scattering processes.