Airborne and spaceborne synthetic aperture radar observations of ocean waves

Measuring the relationship between wind stress and sea state in the open ocean in the presence of swell

“…But the wave buoys cannot sense waves with wavelengths less than twice their diameters, about 2 ni. The wind stress we measure, even if it may represent, for very old seas, an average frictional stress caused by the action of the turbulent wind on high-slope ripples with wavelengths of a few centimetres (the Chamock (1955) point of view), can only be related to the state of the shortest-wavelength waves sensed by the buoys, that is, 4 m. This is nearly two orders of magnitude longer than the waves actually sensed by the radar through the Bragg scattering niechanism (see the article by Vachon et al (1994) in this issue). The wind stress/sea-state relation we measure assumes that the anomaly of the wind stress above the long-fetch, deep-ocean values reported in Smith (1980) -which follow the Chamock relation…”

On the homogeneity of the wave field in coastal areas as determined from ERS-2 and RADARSAT synthetic aperture radar images of the ocean surface

“…In particular, the fact that RADARSAT SAR uses HH polarization does not seem to have a negative effect in comparison with ERS which uses VV polarization, on its ability to observe the ocean wave field in the area of study. It has already been established that a large range to velocity ratio results in SAR image spectra that are more susceptible to non-linear imaging processes and azimuth spectral cut-off (Vachon, et al, 1994). The small differences in the R/V parameter between the ERS and RADARSAT SAR systems, however, shows no noticeable effect on their abillity to detect wave features in the coastal zone with the desired spatial detail.…”

Monitoring Coastal Erosion by Using Wave Spectrum in the Case of Constructions of Small Islands Offshore Songkhla Coast

“…After we set up all parameters mentioned above and had run model. The wave spectrum as the 6 yellow points of along the Songkhla coast in Figures 4-9 was calculated [12,13].…”