Backscattering Cross-Section Incident Dependence by Reflected Pulse Shape Using a Fixed Antenna with the Wide Antenna Pattern

To study and use the short-wave part of the wave spectrum in model constructions, it is necessary to learn how to measure them. However, in marine environments, the measurement of the short-wave part of the wave spectrum is difficult. The development of new instruments for measuring the “roughness” of the short-wave part of the wave spectrum (wavelength up to 2 cm) is extremely urgent and important. This information is in demand by specialists studying the interaction of the atmosphere and the ocean, developing numerical models of wind waves. This paper presents a method for calculating the dependence of the reflected radiation power on the angle of incidence without changing the orientation of the sonar antenna. The new method is based on the geometry of the interaction of the emitted acoustic pulse with the sea surface. For verification, the developed analytical model of the shape of the reflected acoustic pulse and the conducted numerical study of the shape of the pulse from the parameters of surface waves are used. Further, the dependence of the reflected radiation power on the angle of incidence can be used to determine the slope variance. The slope variance retrieval method is like that used for processing data from the GPM and CFOSat mission satellites. The paper investigates the efficiency of the approach for determining the dependence of power on the incidence angle at different depths, pulse duration, wind speeds and wind fetch. Even though the problem is considered for sonar, the proposed approach will be valid for radar as well.