Zhang Hongchen, Zhou Shihong, Liu Changpeng, Qi Yubo
University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China.
State Key Laboratory of Acoustics, Institute of Acoustics, Chinese Academy of Sciences, Beijing 100190, China.
J Acoust Soc Am. 2024 Aug 1;156(2):1148-1164. doi: 10.1121/10.0028229.
Dispersion and multipath effects contribute to the complexity of the shallow water acoustic field. However, this complexity contains valuable information regarding both the waveguide and the acoustic source. The horizontal wavenumber and relative amplitude of the modes comprising the acoustic field are crucial pieces of information for addressing acoustic inversion problems in shallow water. However, when employing a horizontal array to extract this information, limitations arise due to array aperture and signal-to-noise ratio constraints. To attempt to solve these challenges, the approach of spatial domain dedispersion transform and frequency domain accumulation is proposed. The objective can be attained by leveraging broadband source with slowly varying phase spectrum or known phase spectrum under the constraints of small aperture arrays and low signal-to-noise ratio. Additionally, the approach is validated on dual-hydrophone horizontal array by relaxing the signal-to-noise ratio requirement. In this paper, theoretical proof of the algorithms' performance is provided, accompanied by analysis of the impact of parameters such as acoustic source bandwidth, the number of elements and array aperture. The effectiveness of the algorithms are validated through simulations and experimental data.
频散和多径效应导致了浅海水声场所具有的复杂性。然而，这种复杂性包含了关于波导和声源的有价值信息。构成声场的模式的水平波数和相对幅度是解决浅海声学反演问题的关键信息。然而，当使用水平阵列来提取这些信息时，由于阵列孔径和信噪比的限制会出现一些问题。为了尝试解决这些挑战，提出了空间域去频散变换和频域积累的方法。在小孔径阵列和低信噪比的约束条件下，通过利用具有缓慢变化相位谱或已知相位谱的宽带源可以实现这一目标。此外，通过放宽信噪比要求，该方法在双水听器水平阵列上得到了验证。本文给出了算法性能的理论证明，并分析了诸如声源带宽、阵元数量和阵列孔径等参数的影响。通过仿真和实验数据验证了算法的有效性。
