低频混响信号中的简正波衰减系数提取方法

提出一种从低频混响信号中提取简正波衰减系数的方法。利用简正波过滤技术对垂直阵混响信号进行分析,获得单阶简正波混响声场。假设海底反向散射矩阵可分离,从单阶简正波平均混响强度中提取出有效海底反向散射矩阵元素,最后利用不同距离上的有效海底反向散射矩阵元素计算出简正波的衰减系数。利用该方法从混响信号中提取出的简正波衰减系数预报的声传播损失和相同海域实测声传播损失一致。该简正波衰减系数提取方法有效避免了海底散射衰减和简正波传播衰减耦合的问题,同时对海底参数反演和水声环境的快速评估也具有重要的意义。 

Extraction of mode attenuation coefficient from low frequency reverberation signal

A method of extracting mode attenuation coefficient from low frequency reverberation signal was proposed. Traditional normal mode filtering technique was used to get single mode reverberation field firstly.Based on assumption of separability of bottom model back-scattering matrix,effective back-scattering matrix elements were gotten from single mode average reverberation intensity.Finally,mode attenuation coefficient was extracted by comparing effective backscattering matrix element at different range.The extracted mode attenuation coefficient was used to predict sound propagation field at the same experiment area.The result shows that the predicted transmission loss line agrees well with measured transmission loss line.This method avoided coupling between bottom scattering attenuation and normal mode propagation attenuation.Research on extraction of mode attenuation coefficient from low frequency reverberation signal is useful for both geoacoustic inversion and rapid underwater environment assessment.