Surface wave scattering theory is presented as a new method for analyzing teleseismic surface wave data. Using surface wave scattering integrals the effect of lateral heterogeneity both on the surface wave coda generation and on the direct surface wave is described. Since the employed scattering theory for the forward problem is linear, the inverse problem can conveniently be solved in the leas...

Optical tomography schemes using non-linear optimisation are usually based on a Newton-like method involving the construction and inversion of a large Jacobian matrix. Although such matrices canbe efficiently constructed using a reciprocity principle, their inversion is still computationally diffcult. In this paper we demonstrate a simple means to obtain the gradient of the objective function d...