Influence of Transceiver Array Aperture Size on Electromagnetic Linear Inverse Scattering From 2-D Objects Embedded in Planarly Multilayered Media

This article studies the effect of transceiver array aperture size on the inversion ability of the linear integral equation-based solver for the electromagnetic (EM) reconstruction of 2-D scatterers embedded inside a planarly multilayered medium. The investigation is performed in three steps. First, we derive the analytical relationship between the spectra of the scattered electric fields at the receiver array and the reconstructable 2-D scatterer spectrum, which is composed of four different spectral components. This is completely different from the single spectral component for the 2-D scatterer directly placed in a homogeneous subsurface region. Second, the singular value decomposition (SVD) is adopted to compute the discretized integral operator’s right-singular function whose spectrum can also reflect the reconstructable 2-D scatterer spectrum but with the wave attenuation and evanescent mode contribution taken into account. The obtained spectrum shows a “bandstop” feature in the vertical direction with a decrease in the transceiver array aperture size, which is totally different from the “bandpass” feature for the 2-D scatterer embedded in the homogeneous subsurface region. Third, the features of the reconstructable spectrum of the 2-D scatterer embedded inside a planarly multilayered medium, especially the “bandstop” feature, are validated in a series of numerical experiments.