PARAMETRIC RADIATION ANTENNA FOR HYDROACOUSTIC MONITORING OF THE WATER BODY SURFACE: ANALYSIS OF APPLICATION POSSIBILITIES IN WAVE MEASURING EQUIPMENT (REVIEW)

The article considers the use of a parametric radiating antenna (PRA) as a source of a low-frequency ultrasonic signal with tunable characteristics for wave measuring equipment used for hydroacoustic monitoring of the water surface of a coastal area, for example, in remote assessment of the degree of waves when measuring hydroconditions. The results of model experiments on studying the patterns of ultrasonic field scattering during underwater irradiation of both smooth and wind-disturbed water–air interfaces are discussed. The data analysis allowed us to refine the PRA model as a tool for echo detection of objects in shallow water near the acoustically soft water–air interface, employing the imaginary source method. An informative feature is proposed and the basics of the method for measuring the parameters of a rough sea surface using nonlinear acoustics effects are discussed, for example, for the mode of broadband irradiation with ultrasonic signals from the bottom.