Sub-satellite validation using ultrasonic wave gauge: In-situ measurements of surface waves slope variance and other parameters of surface waves

This paper presents the results of field measurements of surface waves parameters obtained in the expedition to a fixed offshore platform in the Black Sea near the Katsiveli settlement in 2015. For the first time experimentally confirmed the efficiency of the new method of directly measuring the slope variances and other surface waves parameters affect the scattering of ultrasound and microwaves. The method is based on the analysis of spectral and energy characteristics of the reflected acoustic waves at underwater surface waves observation. A feature of this method is the simultaneous use of multiple antennas with different radiation patterns. The scheme of measurements with a single radiating and three receiving antennas with different radiation patterns implemented in the acoustical wave gauge manufactured in the IAP RAS. Sensing of the water surface occurs vertically, so that the scattering occurs in quasispecular area. This measurement scheme allows retrieving all the parameters of surface waves that effect on scattering cross-section, the width and the shift of Doppler spectrum of the reflected radiation. String wave gauge used in the experiments to control the effectiveness of a new method. Using of string wave gauge is a standard for precision measurements of surface waves.