Acoustic vector-sensor correlations in ambient noise
Acoustic vector-sensor correlations in ambient noise
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DOI：
10.1109/48.946508
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发表时间：
2001-07-01
影响因子：
4.1
通讯作者：
Nehorai, A
中科院分区：
文献类型：
--
作者：
Hawkes, M;Nehorai, A
大多数阵列处理方法需要噪声的相关结构的知识。虽然有时可以从没有放射源的情况下进行的测量中获得这种信息，但这并不总是可能的。此外，现场进行的测量几乎不能用于在部署之前分析系统性能。因此，在各种环境假设下发展相关结构模型是非常重要的。在本文中，我们获得了积分和封闭形式的表达式的自相关和交叉相关的宽带噪声场的声矢量传感器（AVS）的组件之间的空间分布的假设：1）方位角独立; 2）方位角独立和仰角对称;和3）球面各向同性。我们还推导出在相同的假设下，在窄带噪声场的两个空间位移AVS的所有组件之间的互协方差的表达式。这些结果可用于确定声矢量传感器阵列在环境噪声中的噪声协方差矩阵。我们将它们应用于均匀的线性AVS阵列，以评估其波束形成能力和定位精度，通过Cramer-Rao界，在各向同性和各向异性噪声。
Most array-processing methods require knowledge of the correlation structure of the noise. While such information may sometimes be obtained from measurements made when no sources are present, this may not always be possible. Furthermore, measurements made in-situ can hardly be used to analyze system performance before deployment. The development of models of the correlation structure under various environmental assumptions is therefore very important. In this paper, we obtain integral and closed form expressions for the auto- and cross-correlations between the components of an acoustic vector sensor (AVS) for a wideband-noise field, under the following assumptions concerning its spatial distribution: 1) azimuthal independence; 2) azimuthal independence and elevational symmetry; and 3) spherical isotropy. We also derive expressions for the cross-covariances between all components of two spatially displaced AVSs in a narrowband-noise field under the same assumptions. These results can be used to determine the noise-covariance matrix of an array of acoustic vector sensors in ambient noise. We apply them to a uniform linear AVS array to asses its beamforming capabilities and localization accuracy, via the Cramer-Rao bound, in isotropic and anisotropic noise.