Electromagnetic scattering from large steady breaking waves

Microwave backscattering from surf zone waves

“…Lewis and Olin [] and Coakley et al . [] succinctly suggest it is a Lambertian scatterer, for which case the incident angle dependency should follow a cosine law. In Figure , the cos θ (in dB, when compared against normal incidence) expected rate of decay of a Lambertian scatterer has been superimposed on the data.…”

“…To put the data in context, a summary of previous nearshore observations and the present data set are presented in Figure [ Kalmykov et al ., ; Lewis and Olin , ; Haller and Lyzenga , ; Farquharson et al ., ]. We have also included one laboratory data set by [ Coakley et al ., ], and data taken at 3° grazing by McLaughlin et al . [], although for very short waves, thus steepness limited, in a nearshore setting.…”

“…A second known characteristic of the scattering from breaking waves is that the mean Doppler spectrum is subject to broadening and bias to higher frequencies by sporadic, but large power, scattering events. The Doppler peak is shifted to high frequencies by scattering arising from the active breaking portion of the wave [e.g., Smith et al, 1996] with spectral broadening being driven by surface disturbances produced on the Journal of Geophysical Research: Oceans 10.1002/2014JC009880 turbulent front face that have a range of speeds about their spatial mean, which is the local wave celerity [e.g., Fuchs et al, 1999;Coakley et al, 2001;Farquharson et al, 2005]. All locations where breaking waves were identified, this shift and broadening were identified in the Doppler spectra.…”

“…To put the data in context, a summary of previous nearshore observations and the present data set are presented in Figure 18 Lewis and Olin, 1980;Haller and Lyzenga, 2003;Farquharson et al, 2005]. We have also included one laboratory data set by [Coakley et al, 2001], and data taken at 3 grazing by McLaughlin et al [1995], although for very short waves, thus steepness limited, in a nearshore setting. It is worth noting that these previously reported values correspond to peak NRCS, whereas our data has been presented in terms of median NRCS.…”

“…Despite the obviousness of the rough surface assumption, no specific model exists to predict the nature of the rough surface or the apparent independence from environmental parameters found here. Lewis and Olin [1980] and Coakley et al [2001] succinctly suggest it is a Lambertian scatterer, for which case the incident angle dependency should follow a cosine law. In Figure 18, the cos h (in dB, when compared against normal incidence) expected rate of decay of a Lambertian scatterer has been superimposed on the data.…”