Time-domain reconstruction of moderately rough dielectric interfaces via quasi-ray Gaussian beams

The problem of determining the properties of rough surfaces from electromagnetic scattered field data arises in many importance subsurface sensing problems such as underground imaging using data from a ground penetrating radar (GPR). In GPR systems, arrays of above-ground transmitters and receivers illuminate areas of interest and receive backscattered signals from shallowly buried objects from surface reflections. The shape of the air-ground interface is unknown, and it is a principal corruptor of the backscattered signal from subsurface targets of interest. In order to enhance subsequent detection, classification and inverse scattering processing, it is important to compensate for the distortion introduced by the air-ground interface. As a first step toward this goal, we previously addressed the problem of estimating the profile of one-dimensional (1D) moderately rough dielectric interfaces from a limited number of multifrequency measurements under time-harmonic excitation. In this paper, we extend the approach to the case of time-dependent (short pulse) excitation. The proposed extension is based on a developed Gabor-based narrrow-waisted pulsed-beam representation of short-pulse scattering by moderately rough surfaces.