Raveau M, Feuillade C
Pontifícia Universidad Católica de Chile, Avenida Vicuña Mackenna 4860, Santiago, Chile.
J Acoust Soc Am. 2015 Feb;137(2):539-55. doi: 10.1121/1.4906172.
A model used previously to study collective back scattering from fish schools [Feuillade et al., J. Acoust. Soc. Am. 99(1), 196-208 (1996)], is used to analyze the forward scattering properties of these objects. There is an essential physical difference between back and forward scattering from fish schools. Strong frequency dependent interference effects, which affect the back scattered field amplitude, are absent in the forward scattering case. This is critically important for data analysis. There is interest in using back scattering and transmission data from fish schools to study their size, the species and abundance of fish, and fish behavior. Transmission data can be processed to determine the extinction of the field by a school. The extinction of sound depends on the forward scattering characteristics of the school, and data inversion to provide information about the fish should be based upon a forward scattering paradigm. Results are presented of an analysis of transmission data obtained in September 1995 during an experiment performed in the Gulf of Lion in the Mediterranean Sea [Diachok, J. Acoust. Soc. Am. 105(4), 2107-2128 (1999)]. The analysis shows that using forward scattering leads to significantly larger estimates of fish abundance than previous analysis based upon back scattering approaches.
先前用于研究鱼群集体后向散射的一个模型[Feuillade等人，《美国声学学会杂志》99(1)，196 - 208(1996)]，被用于分析这些物体的前向散射特性。鱼群的后向散射和前向散射存在本质的物理差异。影响后向散射场振幅的强烈频率相关干涉效应在前向散射情况下并不存在。这对数据分析至关重要。人们有兴趣利用鱼群的后向散射和透射数据来研究它们的大小、鱼类的种类和丰度以及鱼类行为。透射数据可以进行处理以确定鱼群对场的消光情况。声音的消光取决于鱼群的前向散射特性，并且为提供有关鱼类信息的数据反演应该基于前向散射范式。给出了对1995年9月在地中海利翁湾进行的一次实验期间获得的透射数据的分析结果[Diachok，《美国声学学会杂志》105(4)，2107 - 2128(1999)]。分析表明，与基于后向散射方法的先前分析相比，使用前向散射会导致对鱼类丰度的估计值显著更大。
