Comparison of Slope, Wave Height, and Radar Spectra, Slope and Hydrodynamic Modulation of Radar Scatter from the Sea

Abstract

Description of Ocean waves usually depends on point measurements of wave height. The important vector slope of the ocean must usually be derived either from point measurements and linear assumptions or from pitch-and-roll buoys that cannot be in the radar footprint. We developed a 35-GHz vector slope gaugehat- terometer using a single switched-beam antenna. It can measure three adjacent height profiles of the ocean, from which we can derive two orthogonal components of the slope. We used the vector slope gauge during the SAXON-FFN experiment in November, 1990. Simultaneous measurements of the orthogonal components of the long-wave slopes and the backscattered power permit determination of the relative contribution to the overall modulation of the radar signal by slope modulation and hydrody- namic modulation of Bragg-resonant ripple amplitude.