Cray Benjamin A, Evora Victor M, Nuttall Albert H
Naval Undersea Warfare Center Division, 1176 Howell Street, Newport, Rhode Island 02891-1708, USA.
J Acoust Soc Am. 2003 Mar;113(3):1526-32. doi: 10.1121/1.1543851.
The theoretical directivity of a single combined acoustic receiver, a device that can measure many quantities of an acoustic field at a collocated point, is presented here. The formulation is developed using a Taylor series expansion of acoustic pressure about the origin of a Cartesian coordinate system. For example, the quantities measured by a second-order combined receiver, denoted a dyadic sensor, are acoustic pressure, the three orthogonal components of acoustic particle velocity, and the nine spatial gradients of the velocity vector. The power series expansion, which can be of any order, is cast into an expression that defines the directivity of a single receiving element. It is shown that a single highly directional dyadic sensor can have a directivity index of up to 9.5 dB. However, there is a price to pay with highly directive sensors; these sensors can be significantly more sensitive to nonacoustic noise sources.
本文介绍了一种单一组合式声学接收器的理论指向性，该装置能够在同一位置测量声场的多个量。该公式是通过在笛卡尔坐标系原点附近对声压进行泰勒级数展开而推导出来的。例如，二阶组合接收器（称为并矢传感器）测量的量有声压、声质点速度的三个正交分量以及速度矢量的九个空间梯度。幂级数展开可以是任意阶的，被转化为一个定义单个接收元件指向性的表达式。结果表明，单个高指向性并矢传感器的指向性指数可达9.5 dB。然而，高指向性传感器也有代价；这些传感器对非声学噪声源可能会明显更敏感。
