海底掩埋物的目标强度和回声信混比

详细信息

The target strength and echo-to-reverberation ratio of a buried target in sediment

School of Naval Architecture, Ocean and Civil Engineering, State Key Laboratory of Vibration, Shock & Noise, Shanghai Jiao Tong University Shanghai 200030

摘要: 基于两种流体介质中声散射的修正的Kirchhoff近似,导出计算掩埋物回声的近似公式。应用回声计算的板块元方法和底质的地声模型,能够计算任意形状刚性掩埋物的回声特性。海底沉积层的影响主要反映在声波在底质中传播的衰减。界面的作用主要表现在声波经过两次折射或透射产生的损失。计算结果表明,用常规方式探测掩埋物时回声信混比总是很小,探测是十分困难的。

Abstract: An approximate formula is derived to calculate the echo from a buried target in the sediment by the modified Kirchhoff approximation of the scattering in two liquid mediums. The echo characteristics of buried rigid targets with arbitrary shapes can be calculated by means of the planar element method and geoacoustic model of the sediment. The effects of sediment are mainly the loss of the sound propagation in the sediment and the effects of the interface are the loss generated by refraction and transmission when the wave through the interface two times. The calculation results show the echo-to-reverberation ratio of a buried target is always very low so that the detection by conventional methods is quite difficult.