海底单参数频域反演与沉积物分类

为了快速获取海底声学特性,从降低反演参数维数入手,提出一种基于海底单参数(小掠射角下海底反射损失随掠射角的变化率)的频域反演方法,并用于沉积物分类。在海底单参数模型基础上,对海底反射信号进行频域相关处理,利用几何射线理论,推导获得海底单参数与归一化频域自相关系数下降至0.5时频移量之间的关系表达式。通过研究海底单参数与沉积物类型之间的等效关系,对海底沉积物进行分类。对波兰波罗的海实验数据进行实际反演,得到1000~2500 Hz频段内的海底单参数值,进而判定实验海域海底沉积物类型为极细砂。结果表明,根据单参数反演值预报的声传播损失与实验测量值符合较好,利用频域反演结果获得的海底沉积物类型与取样结果一致,验证了实验海域频域反演方法的有效性及分类结果的正确性。 

Single parameter inversion and seabed sediment classification in frequency domain

In order to obtain the seabed acoustic characteristics as efficiently as possible,a single parameter inversion method in frequency domain is proposed by reducing the dimension of inversion parameters,and this method could be applied to the classification of seabed sediments.Based on the single parameter seabed model,correlation processing of the seabed reflected signal is carried out in frequency domain,and the relationship between seabed single parameter and frequency displacement when the normalized frequency-domain autocorrelation coefficient decreases to 0.5 is derived by the geometric ray theory.By studying the equivalent relationship between single parameter and sediment types,the seabed sediments are classified.Combined with the experimental data of Baltic Sea in Poland,the seabed single parameter in the frequency band of 1000~2500 Hz are inverted,and the type of seafloor sediment is very fine sand.The results show that the predicted sound transmission loss with inverted single parameter is in good agreement with the experimental value,and the seabed sediment type obtained by the inversion results are consistent with the sampling results.It is proved that the classification results are correct and the inversion method in frequency domain is effective.