Title :
Wave tank modelling of strong modulation of radar backscatter due to long waves
Author :
Ermakov, S.A. ; Sergievskaya, I.A. ; Shchegolkov, Yu.B. ; Scott, J.C. ; Stapleton, N.R.
Author_Institution :
Inst. of Appl. Phys., Acad. of Sci., Nizhny Novgorod, Russia
Abstract :
Modulation of radar backscatter due to long wind waves for Ka-band radar has been studied in wave tank experiments at different wind velocities and fetches. The modulation transfer function (MTF) was analysed, and it is shown that the mechanisms of tilt modulation, hydrodynamic straining and modulation of wind stress strongly underestimate the effect when compared with experiment. Radar Doppler shifts were measured and they were shown to be larger than those, connected with free gravity-capillary Bragg waves, and smaller than for bound waves, generated by decimetre-scale dominant wind waves and propagating with their phase velocities. It is shown that the contribution of the bound waves in the short wind-wave spectrum, estimated from the measured Doppler shifts is significant so that these waves can give strong modulation of radar backscatter
Keywords :
backscatter; ocean waves; oceanographic techniques; radar cross-sections; remote sensing by radar; 35 GHz; EHF; Ka-band; backscatter; bound wave; fetch; gravity-capillary Bragg waves; hydrodynamic straining; long wave; measurement technique; modulation transfer function; ocean wave; radar remote sensing; radar scattering; strong modulation; tilt modulation; wave tank experiment; wind stress; wind velocity; Backscatter; Doppler radar; Doppler shift; Hydrodynamics; Phase measurement; Radar measurements; Stress; Transfer functions; Velocity measurement; Wind speed;
Conference_Titel :
Geoscience and Remote Sensing Symposium, 2001. IGARSS '01. IEEE 2001 International
Conference_Location :
Sydney, NSW
Print_ISBN :
0-7803-7031-7
DOI :
10.1109/IGARSS.2001.977057
