浅水中声学粒子运动的测量及其在地声反演中的应用。

Measurement of acoustic particle motion in shallow water and its application to geoacoustic inversion.

作者信息

Dall'Osto David R, Choi Jee Woong, Dahl Peter H

机构信息

Applied Physics Laboratory, University of Washington-Seattle, 1013 NE 40th Street, Seattle, Washington 98105, USA.

Department of Marine Sciences and Convergent Technology, Hanyang University, 55 Hanyangdaehak-ro, Sangnok-gu Ansan, Gyeonggi-do 15588, Korea.

出版信息

J Acoust Soc Am. 2016 Jan;139(1):311-9. doi: 10.1121/1.4939492.

DOI:10.1121/1.4939492

PMID:26827027

Abstract

Within an underwater acoustic waveguide, the interference among multipath arrivals causes a phase difference in orthogonal components of the particle velocity. When two components of the particle velocity are not in phase, the fluid particles follow an elliptical trajectory. This property of the acoustic field can be readily detected by a vector sensor. A non-dimensional vector quantity, the degree of circularity, is used to quantify how much the trajectory resembles a circle. In this paper, vector sensor measurements collected during the 2013 Target and Reverberation Experiment are used to demonstrate the effect of multipath interference on the degree of circularity. Finally, geoacoustic properties representing the sandy sediment at the experimental site are inverted by minimization of a cost function, which quantifies the deviation between the measured and modeled degree of circularity.

摘要

在水下声波导中，多径到达信号之间的干涉会导致质点速度正交分量出现相位差。当质点速度的两个分量不同相时，流体粒子会沿椭圆形轨迹运动。这种声场特性可通过矢量传感器轻松检测到。一个无量纲矢量量，即圆度，用于量化轨迹与圆的相似程度。本文利用2013年目标与混响实验期间收集的矢量传感器测量数据，来证明多径干涉对圆度的影响。最后，通过最小化一个成本函数来反演代表实验场地沙质沉积物的地声学特性，该成本函数量化了测量圆度与建模圆度之间的偏差。