An improved theory for the radar imaging of underwater bottom topography based on a three-scale model

An improved composite surface model for radar imaging of underwater bottom topography in tidal waters is presented. The model includes contributions to the radar backscatter which are associated with the intermediate-scale surface slope distribution within the radar resolution cell. They increase the theoretical radar signatures of bottom topographic features for high radar frequencies by more than one order of magnitude. Not only tilt modulation but also hydrodynamic modulation of the Bragg waves by longer surface waves is taken into account. The predicted radar signatures depend on the polarization as well as on the azimuthal (up-wind/downwind) look direction of the radar