Acoustics Division, Naval Research Laboratory, Washington, DC 20375, USA.
J Acoust Soc Am. 2010 Jan;127(1):73-83. doi: 10.1121/1.3257211.
Waveguide invariant theory is applied to horizontal line array (HLA) beamformer output to localize moving broadband noise sources from measured acoustic intensity striation patterns. Acoustic signals emitted by ships of opportunity (merchant ships) were simultaneously recorded on a HLA and three hydrophones separated by 10 km during the RAGS03 (relationship between array gain and shelf-break fluid processes) experiment. Hough transforms are used to estimate both the waveguide invariant parameter "beta" and the ratio of source range at the closest point of approach to source speed from the observed striation patterns. Broadband (50-150-Hz) acoustic data-sets are used to demonstrate source localization capability as well as inversion capability of waveguide invariant parameter beta. Special attention is paid to bathymetric variability since the acoustic intensity striation patterns seem to be influenced by range-dependent bathymetry of the experimental area. The Hough transform method is also applied to the HLA beam-time record data and to the acoustic intensity data from three distant receivers to validate the estimation results from HLA beamformer output. Good agreement of the results from all three approaches suggests the feasibility of locating broadband noise sources and estimating waveguide invariant parameter beta in shallow waters.
波导不变理论应用于水平直线阵（HLA）波束形成器的输出，以从测量的声强条纹图案中定位移动的宽带噪声源。在 RAGS03（阵列增益与陆架边缘流体过程的关系）实验中，机会船（商船）发出的声信号同时被 HLA 和三个相距 10 公里的水听器记录。霍夫变换用于估计波导不变参数“β”和源到最近接近点的距离与源速度的比值，从观察到的条纹图案。宽带（50-150-Hz）声数据用于演示源定位能力以及波导不变参数β的反演能力。特别注意水深变化，因为声强条纹图案似乎受到实验区域的距离相关水深的影响。霍夫变换方法也应用于 HLA 波束时间记录数据和声强数据从三个远程接收器，以验证 HLA 波束形成器输出的估计结果。所有三种方法的结果都很好地一致，这表明在浅水中定位宽带噪声源和估计波导不变参数β是可行的。
