FN Archimer Export Format
PT J
TI Scattering From Nonlinear Gravity Waves: The "Choppy Wave" Model
BT 
AF NOUGUIER, Frederic
   GUERIN, Charles-Antoine
   CHAPRON, Bertrand
AS 1:1;2:1;3:2;
FF 1:PDG-ODE-LOPS-SIAM;2:;3:PDG-DOP-DCB-OPS-LOS;
C1 Univ Sud Toulon Var, CNRS, LSEET, F-83957 La Garde, France.
   IFREMER, Lab Oceanog Spatiale, F-29280 Plouzane, France.
C2 UNIV TOULON, FRANCE
   IFREMER, FRANCE
SI BREST
SE PDG-ODE-LOPS-SIAM
   PDG-DOP-DCB-OPS-LOS
IN WOS Ifremer jusqu'en 2018
   copubli-france
   copubli-univ-france
IF 2.485
TC 22
UR https://archimer.ifremer.fr/doc/00018/12974/10175.pdf
LA English
DT Article
DE ;Nonlinear gravity waves;remote sensing;rough surfaces;scattering;sea clutter;undressed spectrum
AB To progress in the understanding of the impact of nonlinear wave profiles in scattering from sea surfaces, a nonlinear model for infinite-depth gravity waves is considered. This model, termed as the "Choppy Wave" Model (CWM), is based on horizontal deformation of a linear reference random surface. It is numerically efficient and enjoys explicit second-order statistics for height and slope, which makes it well adapted to a large family of scattering models. We incorporate the CWM into a Kirchhoff or small-slope approximation and derive statistical expressions for the corresponding incoherent cross section. We insist on the importance of "undressing" the wavenumber spectrum to generate a nonlinear surface with a prescribed spectrum. Interestingly, the inclusion of nonlinearities is found to be practically compensated by the spectral undressing process; an effect which might be specific to the CWM and needs to be investigated in the framework of fully nonlinear models. Accordingly, the difference between the respective normalized radar cross section is rather small. The most noticeable changes are faster azimuthal variations and a slight increase of the radar returns at nadir. A statistical analysis of sea clutter in the framework of a two-scale model is also performed at large but nongrazing incidence. It shows a pronounced polarization dependence of the distribution of large backscattered amplitudes, the tail being much larger in horizontal polarization and for small resolution cell. Surface nonlinearities are shown to increase the tail of the amplitude distribution, as expected. Less obviously, their relative impact is found lesser in horizontal polarization. This raises the question of the actual contribution of nonlinearities in radar sea spikes at nongrazing angles.
PY 2010
PD DEC
SO Ieee Transactions On Geoscience And Remote Sensing
SN 0196-2892
PU Ieee-inst Electrical Electronics Engineers Inc
VL 48
IS 12
UT 000284361800004
BP 4184
EP 4192
DI 10.1109/TGRS.2010.2050694
ID 12974
ER

EF