Dobson semi-empirical model and dielectric complex permittivity are used to represent real and imaginary parts of soil dielectric constant. Soil surface is simulated with exponential distribution model and Monte Carlo method. Composite electromagnetic scattering from soil surface and partially buried multiple columns with rectangular cross-section is studied with finite difference time domain method. It shows that composite scattering coefficient oscillates with scattering angle. Root mean square of soil surface, soil moisture content, dielectric constant of target and incidence angle have great influence on composite scattering coefficient. Correlation length of soil surface, width, height, distance of target section, and dip angle have weak influence on composite scattering coefficient. Buried depth of target hardly has effect on composite scattering coefficient. Compared with other numerical methods, finite difference time domain method obtains higher accuracy, and reduces calculation time and amount of memory occupying as well. It can be used to calculate complex scattering from rough ground and sea surface with nearby arbitrary multiple targets.

To investigate electromagnetic scattering from layered rough surface by method of moment, a direct domain decomposition method is used to derive electromagnetic integral equation of layered rough surface. Combining with wave equation and Green's function, electromagnetic integral equations of layered rough surface are obtained by applying Green's theorem to each space divided by rough surface. Then integral equation is discretized using method of moment. Angular distributions of electromagnetic scattering coefficient from ground covered with snow are obtained with numerical calculation, in which snow surface and ground are described with 1D band-limited Weierstrass fractal spectrum and Monte Carlo method. Accuracy of the domain decomposition is demonstrated by finite difference time domain results. Through analyzing scattering coefficient that varies with parameters of snow and ground, medium parameters of snow and soil, parameters of incident wave, the complete scattering characteristics are obtained.

To meet requirement for measurement and detection of target buried partially beneath a rough surface, rough snow surface and soil surface is simulated in model of exponential type distribution rough surface with Monte Carlo method. Wide-band composite scattering from rough soil surface covered with snow and a column with rectangular cross-section buried partially is studied using finite difference time domain(FDTD). Frequency responses of wide-band composite scattering coefficient is obtained. Wide-band composite scattering coefficients varying with root-mean-square and correlation length of rough snow surface and soil surface, type of snow, thickness of snow layer, moisture capacity of soil, geometric parameter, tilt angle and buried depth of column and incident angle of electromagnetic wave are calculated. It shows that influences of root-mean-square and correlation length of rough snow surface on wide-band composite scattering coefficient are unobvious, but influences of other parameters on wide-band composite scattering coefficient are remarkable and complex.

Electromagnetic wave transmission through 1D band-limited Weierstrass fractal rough surfaces of layered medium is investigated with a hybrid method based on method of moment (MoM) and Kirchhoff approximation (KA). The upper rough surface and the under rough surface are divided into MoM region and KA region, respectively. Transmission coefficient as a function of scattering angle of transmission wave is obtained. Influences of fractal dimension, height root mean square, permittivity of substrate medium, permittivity and mean layer thickness of intermediate medium, frequency of incident wave on transmission coefficient are discussed. It shows that transmission coefficient is affected by parameters of upper rough surface considerably.

Composite electromagnetic scattering of 1D band-limited Weierstrass fractal layered rough land surface and a conducting column with rectangular cross-section is studied with FDTD.Composite scattering coefficient with varying scattering angle is obtained based on bistatic scattering coefficient.Influence of root-mean-square of height fluctuation,dimension of fractal,parameters of the middle layer medium,lower medium and conducting column with rectangular cross-section on composite scattering coefficient is discussed.

Optical wave transmission through slightly rough surface of three layered medium is studied. Transmission coefficients with different polarization are derived using a small perturbation method. A Gaussian rough surface is used to describe rough surface of layered medium. Influence of permittivity of layered medium, mean layer thickness of intermediate medium, roughness surface parameters and incident wavelength on the transmission coefficient of HH polarization is diacussed.