Proudman Oceanographic Laboratory, Joseph Proudman Building, 6, Brownlow Street, Liverpool L3 5DA, United Kingdom.
J Acoust Soc Am. 2009 Dec;126(6):2905-17. doi: 10.1121/1.3242374.
Measurements are presented from a multi-frequency acoustic backscatter study of aqueous suspensions of irregularly shaped quartz sediments having broad particle size distributions. Using the backscattered sound from a homogenous suspension, measurements of the ensemble backscatter form function and ensemble normalized total scattering cross section were obtained. Three different size distribution types are examined; namely Gaussian, log-normal, and bi-modal distributions, each covering a range of particle sizes similar to those observed in sandy marine environments near the seabed. The measurements of ensemble scattering are compared with theoretical predictions, derived by integrating the intrinsic scattering properties of the sediments over the probability density functions of the size distributions used in the present study. The results show that the ensemble scattering parameters are significant functions of both the width and type of size distribution in suspension. The impact of errors in size distribution width on inversion predictions of both mean size and suspended concentration is also examined. The validity of the theoretical predictions is discussed, along with the implication of the inversion results for using acoustic backscatter data to measure suspended concentration and particle size in sandy marine environments.
本文介绍了一项多频声波反向散射研究的结果，该研究针对的是具有较宽粒径分布的不规则形状石英沉积物的水相悬浮液。利用均匀悬浮液反向散射的声波，获得了总体反向散射形态函数和总体归一化总散射截面的测量值。本文研究了三种不同的粒径分布类型，即高斯分布、对数正态分布和双峰分布，每种分布都涵盖了与海底附近海洋砂质环境中观察到的类似的粒径范围。将总体散射的测量值与通过将沉积物的固有散射特性积分到本研究中使用的粒径分布的概率密度函数而得出的理论预测进行了比较。结果表明，总体散射参数是悬浮液中粒径分布的宽度和类型的显著函数。还研究了粒径分布宽度误差对平均粒径和悬浮浓度反演预测的影响。本文还讨论了理论预测的有效性，以及利用声波反向散射数据测量海洋砂质环境中的悬浮浓度和粒径的反演结果的意义。
