Examining the effect of depth and size of the scatterer in inverse scattering of surface waves

Abstract

Summary The purpose of this study is to understand the effect of the depth and size of the scatterers in imaging of the scatterers by scattered surface waves. In the study, the method, which considers three dimensional elastodynamic wave propagation and scattering in a laterally invariant embedding is used. The scattered wavefield is expressed as a domain type integral representation by using the Born approximation. In a halfspace several numerical models, scatterers at different depths with different sizes, as well as different density contrasts are considered and the success of the estimation of the density contrast, the size and the location of the scatterer are examined. It is seen that, for all cases, as the depth of the scatterer increases, the estimated density contrast values differs from the actual value. This is due to the exponential decay of the amplitude of surface waves with depth. Although the estimation of the actual density contrast values becomes difficult, it is still possible to estimate the size and the depth of the scatter accurately, as long as the depth is less than one dominant wavelength.