Du Shiyu Sandy, Wong Kainam Thomas, Song Yang, Nnonyelu Chibuzo Joseph, Wu Yue Ivan
School of General Engineering, Beihang University, Beijing, 100191, China.
School of Electrical and Electronic Engineering, Nanyang Technological University, 639798, Singapore.
J Acoust Soc Am. 2022 Feb;151(2):1158. doi: 10.1121/10.0009312.
Directional sensors, if collocated but perpendicularly oriented among themselves, would facilitate signal processing to uncouple the azimuth-polar direction from the time-frequency dimension-in addition to the physical advantage of spatial compactness. One such acoustical sensing unit is the well-known "tri-axial velocity sensor" (also known as the "gradient sensor," the "velocity-sensor triad," the "acoustic vector sensor," and the "vector hydrophone"), which comprises three identical figure-8 sensors of the first directivity-order, collocated spatially but oriented perpendicularly of each other. The directivity of the figure-8 sensors is hypothetically raised to a higher order in this analytical investigation with an innocent hope to sharpen the overall triad's directionality and steerability. Against this wishful aspiration, this paper rigorously analyzes how the directivity-order would affect the triad's "spatial-matched-filter" beam's directional steering capability, revealing which directivity-order(s) would allow the beam-pattern of full maneuverability toward any azimuthal direction and which directivity-order(s) cannot.
如果方向传感器相互并置但彼此垂直定向，除了具有空间紧凑性的物理优势外，还将有助于信号处理，以便从时频维度中解耦方位 - 极向。一种这样的声学传感单元是著名的“三轴速度传感器”（也称为“梯度传感器”、“速度传感器三元组”、“声学矢量传感器”和“矢量水听器”），它由三个相同的一阶8字形传感器组成，在空间上并置但彼此垂直定向。在本分析研究中，假设将8字形传感器的指向性提高到更高阶，天真地希望提高整个三元组的方向性和可操纵性。与这种一厢情愿的愿望相反，本文严格分析了指向性阶数将如何影响三元组的“空间匹配滤波器”波束的方向转向能力，揭示了哪些指向性阶数将允许波束方向图向任何方位方向进行完全可操纵，哪些指向性阶数则不能。
