Bottom Reverberation For Large Receiving Depth In Deep Water

Ocean reverberation is an important issue in underwater acoustics,which usually influences the working performance of the active sonars significantly.The deep-water reverberation data were collected from the South China Sea experiment including the reverberation signals at large receiving depths near the bottom,which shows that wave intensity increases obviously at some moments with increasing time.To deep analyze the data,a uniform bottom-reverberation model is proposed,which can calculate monostatic and bistatic reverberation intensity and explain the generation process of deep-water reverberation.The mesh method is first used in this model by dividing bottom scatterers into a number of grids.Then reverberation is calculated based on the exact time of scattering signal generated on each grid.Due to exact arrival time,the presented model can provide more accurate result than classical models,in which scatterers are usually treated as circular rings or elliptical rings.Numerical results are compared with experimental reverberation with different receiving distances and depths.The simulated and experimental results agree well overall for large receiving depths,whereas agreement reduces for receiving depth close to the sea surface.The analytical results indicate that the applied scattering coefficient is suitable for this experimental sea area,and meanwhile verify that this scattering model is more accurate for low-angle bottom backscatterers corresponding to the reverberation at large receiving depths.In view of the current national Marine strategy for the development of far-reaching sea,the research of this paper can provide a technical basis for the analysis of deep-sea reverberation characteristics and the suppression of reverberation,which has important scientific significance and application value.