Research on Reverberation Signal under Ice Based on Physical Acoustic Modeling and Its Related Characteristics

Ocean reverberation is an important factor to affect the detection performance of active sonar, especially, in ice-covered sea areas. Because the interaction between ice and water will produce strong reverberation field, which have a great impact on the acoustic detection and communication performance. Physical acoustic method is firstly used to study the reverberation characteristics under the rough ice surface in this paper. Based on Kichhoff approximation, a Helmholtz scattering model is established under rough ice surface, and obtain the reverberation signal under ice, and analyzed its statistical and related characteristics. In order to simulate the ice surface which is in a fluctuating state, the stochastic process description method is used to describe the random fluctuating rough surface According to the reflection theory of ice-water interface, obtaining the relationship between the reflection coefficient of ice-water interface element and the incident angle function. The Hotz integral acoustic scattering model is used to obtains the reverberation signal under ice and analyze its correlation characteristics. At the same time, the correlation characteristics of the reverberation signal under ice is analyzed by analyzing the test data in Songhua River. The analyzed results show that the time correlation radius decreases and the correlation decreases with the increase of the signal frequency, and the spatial correlation coefficient shows oscillation attenuation relationship with the increase of the array spacing.