Diffraction Tomography In Layered Background

Diffraction tomography has been investigated mainly with respect to homogeneous background. However, for seismic crosshole surveys carried out in sedimentary environment, layered medium would be the more appropriate background. A diffraction tomography algorithm with respect to layered background is derived by applying the distorted wave Born approximation to the wave solution and by using background solutions appropriate to a layered medium. The formalism employs eigenstates defined with respect to the vertical coordinate for solution and data representation. A 2-D inversion is reduced to a set of independent 1-D inversions. The formalism generalizes previous results with respect to homogeneous background.