Ka-Band Doppler Scatterometry: A Strong Wind Case Study

Global joint measurements of sea surface winds and currents are planned using satellite-based Doppler scatterometers operating in the Ka-band to achieve improved spatial resolution retrieval accuracy. Still, knowledge backscatter properties is poor, particularly, at high (>20 m s−1). Sea radar cross-section Ka-band, contrast that lower frequency Ku-/X-/C-/L-bands, likely more sensitive spray, small-scale particles typically present winds. In this paper, tower-based field data collected by a continuous dual-co-polarized during strong offshore wind event (with speed reaching 33 s−1) analyzed. This katabatic (≈12 h long) was also recorded supplementary wave, wind, current sensors. At wave fetch ≈1 km, maximum wavelength observed waves ≈10 m. For such extremely young wind–sea conditions, an apparent spray generation gusts. Radar were performed 20∘ 45∘ incidence angles, mostly for cross- up-wind azimuth look geometry. Based on these measurements, previously developed empirical model tested compared with other published geophysical functions. Dual-co-polarized used infer resonant Bragg non-Bragg scattering components assess short spectrum, which shows clear tendency saturation The presence signatures high-frequency tails spectra, but their overall contribution centroid weak. Hence, standard modulation transfer function approach moderate still applicable interpreting wave-induced velocity inferring currents. These results can be useful understanding scatterometry tropical cyclones.