Estimating geomorphology and setting the scale partition with a composite-roughness scattering model

Scattering from the seafloor is often assumed to be controlled by two spatial scales: the larger scale associated with reflections from plane facets and the smaller one associated with diffuse scattering from height variations. Choosing the wavenumber for this partitioning has proven to be important but troublesome. For this work scattering data is simulated using Helmholtz-Kirchhoff or physical optics theory and selected input geomorphology. These data are inverted using a simpler two-scale roughness model. The work introduces a new criterion for effecting this partition based on setting a roughness parameter equal to unity. The criterion is shown to be valid for the cases analyzed based on the ability of the inversion model to recover the input geomorphology