Utilization of elastic wave mode conversion in electromagnetic diffraction tomographic imaging schemes

In contrast to acoustic and electromagnetic waves elastic waves appear with two different wave speeds and polarizations, i.e. as longitudinal pressure and transverse shear waves. They are converted into each other at boundaries of material discontinuities; therefore, scattered elastic wave fields always contain a superposition of both modes. A separation is conveniently possible in K-space through proper projections of spatially Fourier transformed data allowing for a subsequent inversion in terms of conventional electromagnetic diffraction tomography yielding pressure and shear wave images separately. The resulting algorithm is applied to data obtained for buried objects (tendon ducts) in concrete.