Full-range sea surface spectrum in nonfully developed state for scattering calculations

A new form for the spectrum of the ocean surface vertical displacements is derived for the case of nonfully developed states. The gravity range is expressed as a function of the fetch x and the significant slope /spl conint/ as well. The capillary-gravity range is assumed dependent on the wind frict...

Full description

Saved in:
Bibliographic Details
Published in:IEEE transactions on geoscience and remote sensing 1999-03, Vol.37 (2), p.1038-1051
Main Authors: Lemaire, D., Sobieski, P., Guissard, A.
Format: Article
Language:English
Subjects:
Algorithms
Angle of incidence
Applied geophysics
Computation
Earth sciences
Earth, ocean, space
Electromagnetic modeling
Electromagnetic scattering
Exact sciences and technology
Friction
Gravity
Incidence
Internal geophysics
Marine
Marine geology
Mathematical models
Oceans
Radar scattering
Scattering
Sea measurements
Sea surface
Spectra
Spectral shape
Wind speed
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:A new form for the spectrum of the ocean surface vertical displacements is derived for the case of nonfully developed states. The gravity range is expressed as a function of the fetch x and the significant slope /spl conint/ as well. The capillary-gravity range is assumed dependent on the wind friction velocity only. Recent wavenumber spectrum measurements in this spectral domain and ocean conditions are analyzed. Toba's spectral shape is shown to represent correctly these experimental data when updated with an equivalent amplitude factor. An expression for this factor is proposed. It is weakly wind friction velocity dependent, as observed by Mitsuyasu in the late 1970s. The proposed spectrum is then combined with a boundary perturbation model for electromagnetic scattering computations. Empirical scattering models and radar data collocated with assumed ground-truth data are used for comparison. This is shown to give consistent results for both C- and Ku-bands as well as large ranges of wind speeds and incidence angles. Comparisons of backscattering coefficients computed using other sea spectra from the literature are presented. The significant slope is found to be an important factor for scattering at low incidence angles. The proposed spectrum thus constitutes a useful basis for physically based inversion algorithms.
ISSN:0196-2892
1558-0644
DOI:10.1109/36.752222