Title :
Observations of radar backscatter at Ku and C bands in the presence of large waves during the Surface Wave Dynamics Experiment
Author :
Nghiem, S.V. ; Li, Fuk K. ; Lou, Shu-hsiang ; Neumann, Gregory ; McIntosh, Robert E. ; Carson, Steven C. ; Carswell, James R. ; Walsh, Edward J. ; Donelan, Mark A. ; Drennan, William M.
Author_Institution :
Jet Propulsion Lab., California Inst. of Technol., Pasadena, CA, USA
fDate :
5/1/1995 12:00:00 AM
Abstract :
Ocean radar backscatter in the presence of large waves is investigated using data acquired with the Jet Propulsion Laboratory NUSCAT radar at Ku band for horizontal and vertical polarizations and the University of Massachusetts C-SCAT radar at C band for vertical polarization during the Surface Wave Dynamics Experiment. Off-nadir backscatter data of ocean surfaces were obtained in the presence of large waves with significant wave height up to 5.6 m. In moderate-wind cases, effects of large waves are not detectable within the measurement uncertainty and no noticeable correlation between backscatter coefficients and wave height is found. Under high-wave light-wind conditions, backscatter is enhanced significantly at large incidence angles,with a weaker effect at small incidence angles. Backscatter coefficients in the wind speed range under consideration are compared with SASS-II (Ku band), CMOD3-H1 (C band), and Plant´s model results which confirm the experimental observations. Variations of the friction velocity, which can give rise to the observed backscatter behaviors in the presence of large waves, are presented
Keywords :
backscatter; electromagnetic wave scattering; ocean waves; oceanographic techniques; radar applications; radar cross-sections; radar imaging; radar polarimetry; remote sensing; remote sensing by radar; C-band SHF Ku band; Surface Wave Dynamics Experiment; horizontal polarisation; large wave; measurement technique; ocean wave; radar backscatter scattering; radar polarimetry; radar remote sensing; sea surface; significant wave height; vertical polarization; Airborne radar; Backscatter; Laboratories; Measurement uncertainty; Oceans; Polarization; Propulsion; Radar detection; Sea surface; Surface waves;
Journal_Title :
Geoscience and Remote Sensing, IEEE Transactions on