Quad-Pol L-band Scatterometer for Ocean Surface Vector Winds in Extreme Conditions

Ocean Surface Vector Winds (OSVW) are critical inputs for naval operations, numerical weather prediction, tropical cyclone forecasting, and climate monitoring. Traditional satellite scatterometers operating at C- and Ku-band frequencies suffer from significant performance degradation in heavy precipitation, saturating at high wind speeds and failing to capture accurate wind vectors within tropical cyclones, near frontal boundaries, or in regions of intense convection. L-band (~1.2 GHz) active microwave remote sensing offers a compelling alternative due to its minimal attenuation in rain and robust sensitivity across a wider dynamic wind range, including hurricane-force conditions.ÝThis effort explores the technical feasibility of a quad-polarization L-band scatterometer system capable of retrieving high-accuracy OSVW under extreme environmental conditions. The proposed sensor architecture integrates a phased array antenna with electronically steered beamforming and a reconfigurable software-defined radar backend. The system supports dynamic acquisition of co- and cross-polarized radar returns across a broad range of incidence and azimuth angles, enabling multi-look vector retrievals and enhanced robustness against ambiguity. Operating in this configuration allows for improved retrievals of storm structure, including wind radii at hurricane thresholds, gale force winds, and early cyclonic circulation.ÝUnlike fixed-angle radiometers or legacy scatterometers, the quad-pol L-band system is ideal for all-weather performance and high wind accuracy, with a wide swath to enable full coverage of mesoscale oceanic systems. This novel configuration allows for the extension of Geophysical Model Functions into previously undersampled angular and wind regimes. Retrieval algorithms based on multi-angle, multi-pol inversion and physical forward modeling will be tested using simulated data incorporating ocean surface models, rain-induced backscatter, and ionospheric effects such as Faraday rotation.ÝThis capability represents a substantial advancement over existing systems by addressing key gaps in tropical cyclone monitoring and enabling near-real-time wind products critical for maritime situational awareness. The approach is designed for compatibility with small satellite platforms, offering a scalable and cost-effective path toward operational deployment.