College of Meteorology and Oceanography, National University of Defense Technology, Changsha 410073, China.
J Acoust Soc Am. 2023 Jul 1;154(1):255-269. doi: 10.1121/10.0020148.
Source depth estimation is an important yet very difficult task for passive sonars, especially for horizontal linear arrays (HLAs). This paper proposes an efficient two-step depth estimation scheme using narrowband and broadband constructive and deconstructive striation patterns due to interference between the direct (D) and sea surface reflected (SR) arrivals at an HLA on the bottom of deep water. First, the horizontal source-array ranges are derived from triangulation results of solid angle estimates by subarray beamforming. The applicable areas of the method in deep water are investigated through Mento Carlo simulations, assuming different subarray partitioning ways of a given HLA aperture. Second, cost functions are built to match the measured beam intensity striations with modeled ones. To mitigate the spatial smoothing effect of the beam intensity striations during beamforming, a criterion of the largest subarray aperture is established, and a computationally efficient way is presented to model the replicas by the D-SR time delay templates at a single element of the array calculated by ray theory. The performance degradation due to limited source range spans, the distortion of the beam intensity striations, and range estimation errors has been analyzed. Two experimental datasets verify the effectiveness of the proposed method.
声源深度估计对于被动声纳来说是一项非常重要但极具挑战性的任务，尤其是对于水平线性阵（HLA）而言。本文提出了一种基于窄带和宽带相干和非相干条纹图案的高效两步深度估计方案，该方案是由于深海底部 HLA 上的直达（D）和海面反射（SR）到达之间的干涉而产生的。首先，通过子阵波束形成的立体角估计的三角测量结果推导出水平声源-阵列范围。通过蒙特卡罗模拟研究了该方法在深水中的适用区域，假设了给定 HLA 孔径的不同子阵划分方式。其次，构建了代价函数来匹配测量的波束强度条纹与模型化的条纹。为了减轻波束强度条纹在波束形成过程中的空间平滑效应，建立了最大子阵孔径的准则，并提出了一种计算效率高的方法，通过射线理论计算的阵列单个单元的 D-SR 时间延迟模板来对副本进行建模。分析了由于有限的源范围跨度、波束强度条纹的失真以及距离估计误差导致的性能下降。两个实验数据集验证了所提出方法的有效性。
