Multipath EM scattering from breaking ocean waves at grazing incidence
Article first published online: 7 DEC 2012
Copyright 1997 by the American Geophysical Union.
Volume 32, Issue 4, pages 1455–1467, July-August 1997
How to Cite
1997), Multipath EM scattering from breaking ocean waves at grazing incidence, Radio Sci., 32(4), 1455–1467, doi:10.1029/97RS00909., and (
- Issue published online: 7 DEC 2012
- Article first published online: 7 DEC 2012
- Manuscript Accepted: 26 MAR 1997
- Manuscript Received: 1 OCT 1996
The electromagnetic scattering from a breaking water wave with near grazing illumination has been examined using both experimental measurement and numerical calculation. The scattering from a metal model of a breaking wave of 1.2 m wavelength was characterized at grazing angles ranging from 0° to 25° and at frequencies ranging from 6 GHz to 12 GHz. Strong multipath interference is observed in the vertical polarization (VV) backscatter and much weaker interference is seen in the horizontal polarization (HH) backscatter. Scattering from the wave profile both with and without the breaking plume shows that the plume is the dominant scattering feature. Numerical calculation of the scattering from modified surface profiles shows that the interference is due to multipath scattering from the plume and front face of the wave. HH interference is substantially smaller than that of VV because the scatter from the plume in the multipath direction (toward the front face) is greatly reduced owing to the conducting surface boundary conditions. The relative levels of the plume and expected distributed-surface scattering are consistent with the wave-tank measurement of horizontally polarized sea spikes from breaking waves of this scale.