TNO, Oude Waalsdorperweg 63, P.O. Box 96864, 2509 JG The Hague, The Netherlands.
J Acoust Soc Am. 2011 Nov;130(5):3413-20. doi: 10.1121/1.3626125.
Reliable predictions of sea-surface backscattering strength are required for sonar performance modeling. These are, however, difficult to obtain as measurements of sea-surface backscattering are not available at small grazing angles relevant to low-frequency active sonar (1-3 kHz). Accurate theoretical predictions of scattering strength require a good understanding of physical mechanisms giving rise to the scattering and the relative importance of these. In this paper, scattering from individual resonant bubbles is introduced as a potential mechanism and a scattering model is derived that incorporates the contribution from these together with that of rough surface scattering. The model results are fitted to Critical Sea Test (CST) measurements at a frequency of 940 Hz, treating the number of large bubbles, parameterized through the spectral slope of the size spectrum for bubbles whose radii exceed 1 mm, as a free parameter. This procedure illustrates that the CST data can be explained by scattering from a small number of large resonant bubbles, indicating that these provide an alternative mechanism to that of scattering from bubble clouds.
可靠的海面反向散射强度预测对于声纳性能建模至关重要。然而，由于在低频主动声纳（1-3 kHz）相关的小掠射角处无法进行海面反向散射测量，因此很难获得这些预测。要准确预测散射强度，就需要很好地理解产生散射的物理机制及其相对重要性。本文引入单个共振气泡的散射作为一种潜在机制，并推导了一个散射模型，该模型将来自这些气泡的散射与粗糙表面散射的贡献结合在一起。将模型结果拟合到在 940 Hz 频率下的关键海洋测试（CST）测量值，将大泡泡的数量作为一个自由参数，通过半径大于 1 毫米的泡泡的尺寸谱谱斜率来参数化。这一过程表明，CST 数据可以用少量大共振泡泡的散射来解释，这表明这些泡泡提供了一种与泡泡云散射不同的机制。
