scholarly journals An improved composite surface model for the radar backscattering cross section of the ocean surface: 2. Model response to surface roughness variations and the radar imaging of underwater bottom topography

1997 ◽  
Vol 102 (C11) ◽  
pp. 25251-25267 ◽  
Author(s):  
Roland Romeiser ◽  
Werner Alpers
Keyword(s):  
Surface Roughness ◽  
Cross Section ◽  
Bottom Topography ◽  
Ocean Surface ◽  
Radar Imaging ◽  
Surface Model ◽  
Composite Surface ◽  
Backscattering Cross Section ◽  
Model Response ◽  
Radar Backscattering

Kelvin and V-like Ship Wakes Affected by Surfactants

2001 ◽  
Vol 45 (02) ◽  
pp. 150-163
Author(s):  
Gregory Zilman ◽  
Touvia Miloh
Keyword(s):  
Cross Section ◽  
Single Layer ◽  
Ship Wake ◽  
Backscattering Cross Section ◽  
Alternative Approach ◽  
Ship Wakes ◽  
Half Angle ◽  
Radar Backscattering ◽  
The Green Function ◽  
Theoretical Results

Synthetic aperture radar (SAR) ship wake images in light wind and calm sea conditions frequently appear in the form of a bright V with a half-angle of 2 to 3 deg. Sophisticated and conflicting explanations of this phenomenon, based on the Bragg scattering mechanism, have been proposed. There is a belief that the narrow V-wake is not a part of the Kelvin wake. An alternative approach, which is not generally accepted, suggests that short divergent Kelvin waves may contribute to the V-wake imaging although these waves are mixed with unsteady surface waves generated by the ship-induced turbulence. Ship-generated divergent waves contaminated by surfactants and their radar backscattering cross section are studied. The hull of the ship is represented by a single layer of hydrodynamic singularities. The Green function of a point source moving below a free surface covered by surfactants is derived. A closed-form asymptotic solution for the far ship wave wake is obtained. It is used to calculate analytically the corresponding radar backscattering cross section. The radiative, viscous, and surfactant-induced decay of the V-wake brightness along the V-arms is discussed. The theoretical results are compared against available experimental data.

Sign in / Sign up

Export Citation Format

Share Document