Department of Electrical and Computer Engineering, Duke University, P.O. Box 90291, Durham, North Carolina 27708, USA.
J Acoust Soc Am. 2013 Jan;133(1):311-22. doi: 10.1121/1.4770233.
This work concerns the development of field directionality mapping algorithms for short acoustic arrays on mobile maneuverable platforms that avoid the left/right ambiguities and endfire resolution degradation common to longer non-maneuverable line arrays. In this paper, it is shown that short maneuverable arrays can achieve a high fraction of usable bearing space for target detection in interference-dominated scenarios, despite their lower array gain against diffuse background noise. Two narrowband techniques are presented which use the expectation-maximization maximum likelihood algorithm under different models of the time-varying field directionality. The first, derivative based maximum likelihood, uses a deterministic model while the second, recursive Bayes maximum likelihood, uses a stochastic model for the time-varying spatial spectrum. In addition, a broadband extension is introduced that incorporates temporal spectral knowledge to suppress ambiguities when the average sensor array spacing is greater than a half-wavelength. Dynamic multi-source simulations demonstrate the ability of a short, maneuvering array to reduce array ambiguities and spatial grating lobes in an interference dominated environment. Monte Carlo evaluation of receiver operating characteristics is used to evaluate the improvement in source detection achieved by the proposed methods versus conventional broadband beamforming.
这项工作涉及开发用于移动可操纵平台上短声学阵的场方向性映射算法，以避免常见于更长的非可操纵线阵的左右模糊和端射分辨率降低。在本文中，我们将表明，尽管短可操纵阵在干扰主导的情况下对扩散背景噪声的阵列增益较低，但对于目标检测，它们可以实现高比例的可用方位空间。提出了两种窄带技术，它们在时变场方向性的不同模型下使用期望最大化最大似然算法。第一种，基于导数的最大似然，使用确定性模型，而第二种，递归贝叶斯最大似然，使用时变空间谱的随机模型。此外，引入了宽带扩展，该扩展结合了时间谱知识，以在平均传感器阵列间距大于半波长时抑制模糊。动态多源模拟证明了短、可操纵阵在干扰主导环境中减少阵列模糊和空间栅瓣的能力。接收者操作特性的蒙特卡罗评估用于评估所提出的方法相对于传统宽带波束形成在源检测方面的改进。
