An end-to-end simulation of radar signatures from the HI-RES 1 rip feature

Examines the origin of the strong radar signatures from the rip-like feature observed during the First High Resolution Remote Sensing (HIRES-1) experiment, based on an “end-to-end” strategy in which radar signatures are modelled from a full-spectrum wave approach, using surface and subsurface currents, derived from the underlying hydrodynamics. The authors find that it is necessary to include wave-breaking (WB) effects to obtain satisfactory agreement with experiment for the magnitude of the observed radar signature. They accomplish this using an earlier WB model and by introducing an improved WB model. The new model combines the statistically-based, composite model of radar backscatter with a deterministic, feature model that relates the predominant backscatter from breaking waves to a particular geometrical model of a spilling breaker. This is accomplished by using localized WB criteria, based on critical crest acceleration Λ_c information, to determine the probability of breaking, and by extending the feature model so that its assumed geometry may be determined statistically. This allows the authors to eliminate all of the unknown parameters of the feature model using calculations of wave-height spectra