Surface waves are dispersive that means their propagation velocity depends on frequency. Analysing the dispersion provides information about the variability of material properties with increasing depth beyond the surface. Established methods used today (inversion of dispersion curves or wave field spectra) assume that there is no variability of material properties along the profile. This assumption is not satisfied in most applications of practical relevance. To overcome this limitation the full recorded seismograms have to be inverted. The development of an appropriate method is the aim of this project.