f The Rytov approximation aids the resolution of the broad velocity components in non-linear waveform inversion

The bare of non-linear waveform inversion based on the Bom scattering model has been the need of a close starting model -- particularly for the broad components of the velocity field. Without a close starting model the method is susceptible to failure by getting stuck in a local minima (Tarantola, 1990 & Gauthier et al, 1986).