On the reduction of the radar backscatter by oceanic surface films: Scatterometer measurements and their theoretical interpretation

摘要: Abstract During the two SIR-C/X-SAR missions in 1994, surface film experiments were performed North Sea with a 5-frequency/multipolarization scatterometer flown on helicopter, order to investigate reduction of radar backscatter presence quasibiogenic and anthropogenic sea films, particularly, at different wind speeds. Under all conditions encountered this study, measured damping ratio (i.e., from slick-free slick-covered water surface) increases increasing Bragg wavenumber. It is shown that not only Marangoni theory, but also wind-induced effects, primarily energy input by into wave spectrum, have be taken account. The reductions low moderate speeds (3.5–4 m/s 5 m/s) are qualitatively explained means comparison source terms action balance equation. For case high speed (12 theoretical model for ratios developed. Using model, experimental data can well reproduced, absence maximum intermediate wavenumbers (approximately 100 rad/m) interpreted. Furthermore, explain similarities between over films under conditions.