Sensor Arrangement in Through-the Wall Radar Imaging

Abstract

In this paper, the problem of how to spatially sample the scattered field in microwave through-the wall imaging is addressed. To this end, a two-dimensional scalar configuration for a three-layered back-ground medium is considered under a linearized scattering model. The aim is to collect as low as possible measurements by maintaining the same performance in the reconstructions. Accordingly, the number and the positions of the spatial measurement points are determined so that the point-spread function of the resulting semi-discrete problem approximates well the one of the ideal continuous case (i.e., when data space is not sampled at all). It is shown that the resulting measurement spatial positions must be non-uniformly arranged across the measurement domain and their number is generally much lower than the one returned by some literature sampling criteria. Also, the measurement points can be analytically determined by taking into account the geometrical parameters as well as the wall features. Numerical examples are included to check the theoretical arguments.

Transverse Resolution in Through-the-Wall Radar Imaging

“…Equation (1) in operator notation is written as The function v(x) ¼ (e s (x) À e 0 )/e 0 is the so-called contrast function, with e s being the dielectric permittivity of the unknown scatterer, representing the unknown solution of the problem. The function G 2 (x o , x,) is the square of G(x o , x,), that is, the Green function accounting for a three-layered background medium whose spectral representation is reported in [2]. If it is assumed that L. k 0 n and z À L À z o .…”

“…where cðxÞ ¼ ½/ðÀX 0 ; xÞ þ /ðX 0 ; xÞ and gðxÞ ¼ ½/ ðÀX 0 ; xÞ À /ðX 0 ; xÞ To make explicit the dependence of g(x) in terms of x, we need to determine the two refraction points x m1 and x m2 by solving (4). This issue can be simplified by exploiting an equivalent two-layered model (see [2]). This allows one to reexpress the phase term in (3) as…”

“…The electromagnetic wave capability to ''see'' through obstacles, such as walls, doors, and other visually opaque materials, is considered a powerful tool for a variety of applications, both military and civilian. Through-the-wall radar imaging (TWRI) needs to solve an electromagnetic inverse scattering problem within a nonhomogeneous scattering scenario representing the wall [1][2][3]. As is well known, such a problem is nonlinear and ill-posed.…”

Application of the Model of Spots for Inverse Problems

“…Geophysics also uses visualization obtained by sounding the earth with the help of sound or electrical impulses, etc. [ 1 , 4 ]. Imaging in all these areas, with the exception of MRI, is associated with the solution of inverse scattering problems in one or another approximation [ 5 ].…”

Enhancing Deep Learning-Based Antenna Array Coefficient Reconstruction through Optimized Data Management

“…The first dataset is generated through a CUS strategy for collecting the intensity of radiated fields. The second dataset employs an ONUS approach, designed to discard redundant data [31,32,33]. Our primary objective is to assess the impact of these datasets on the U-Net model's performance.…”