Airborne Weather Radar: A theoretical approach for water-surface backscattering and wind measurements

It is widely known that spaceborne synthetic aperture radar (SAR) can provide sea-surface wind field maps that are very useful for applications where knowledge of the sea-surface wind at fine scales is crucial, such as the analysis of waves, ocean circulation, marine meteorology, and the relationships between oceanic and atmospheric systems. Perhaps it is less well known that airborne weather radar (AWR) may also be used for the same purpose. In this article, we present two methods for measuring water-surface backscattering signature and estimating the near-surface wind vector over water using AWR. The latter operates in the ground-mapping mode as a scatterometer. An estimate of the azimuth normalized radar cross section (NRCS) curve of the water surface is obtained from an aircraft's circular or rectilinear flight. The wind vector is retrieved from the azimuth NRCS curve. In this article, some measuring recommendations and algorithms are proposed.