Scattering Of Electromagnetic Pulse Wave From Rough Surfaces

In recent decades, the majority of science and technology workers pay more and more attention to research on scattering of electromagnetic pulse wave from rough surfaces. As the technology of electromagnetic pulse wave is widely used in radar, remote sensing, microwave and millimeter-wave communication, etc., the research on transient electromagnetic field(also called as time-domain electromagnetic field) of electromagnetic pulse wave develop very fastly.This article firstly introduces the research on scattering of electromagnetic pulse wave from Gaussian rough surfaces. By using the two-frequency mutual coherence function by Ishimaru et al. and the Kirchhoff frequency-domain theory about electromagnetic scattering from rough surfaces, we consider the time-domain properties of electromagnetic scattering from Gaussian rough surfaces which is homogeneous and isotropic, derive the expression of two-frequency mutual coherence function under stationary-phase approximation or scalar approximation, discuss the relation between the power of electromagnetic scattering echo and the two-frequency mutual coherence function, calculate the effect of different irradiation size, incidence angle and statistical parameters of rough surfaces on two-frequency mutual coherence function, coherence bandwidth and electromagnetic scattering echo, numerically, and discuss pulse broadening effect at the same time.On the basis of preamble, this article then introduces the research on scattering of electromagnetic pulse wave from non-Gaussian rough surfaces. This article assumes the distribution of rough surfaces is a Gram-Charlier distribution. By using this distribution, we write the expression of two-frequency mutual coherence function and angular correlation function. By using the third-order statistical properties of rough surfaces and the A.K.Fung sea spectrum, we calculate the effect of different incidence angle, wind direction and wind velocity on two-frequency mutual coherence function, coherence bandwidth and electromagnetic scattering echo, numerically, and discuss pulse broadening effect at the same time.