The use of the Born approximation in seismic scattering problems

Summary. In view of recent work on seismic scattering by small-scale heterogeneities in the Earth, which has been based on single-scattering perturbation theory (that is, the Born approximation), we attempt to define the region within which this approximation may be regarded as reasonably accurate. Comparison with the exact solution for scattering by an embedded sphere shows that the inequalities obtained, governing the ranges of the parameters of the problem, are appropriate.
However, application of these constraints on the parameters imply that, in almost all cases, application of the Born approximation to upper and lower mantle scattering is probably invalid.