一种矢量阵近场恒定束宽波束形成方法

摘要

An acoustic vector hydrophone, which possesses better directivity, compact geometry and suppression ability of isotropic noise interference, can measure all the three components of the acoustic particle velocity and the pressure at a single point in space, has been proved to be an effective means to improve the measurement ability of ship-radiated noise. Furthermore, with the combination of multiple vector hydrophones, a vector hydrophone array can obtain a higher measurement gain, which helps to evaluate the noise level of weak signatures. In this paper, a near-field signal model of acoustic vector hydrophone is first established, and then two different beamforming methods which utilize the output of a single vector hydrophone or the different types of output of vector hydrophone array are discussed. Aiming at the design problem of constant beamwidth beamformer (CBB), a near-field CBB method with Kaiser weighting is presented. Making use of the characteristics of Kaiser, the designed beam response is gradually converged to the desired beam response and the design precision of CBB is improved with the adoption of exponential verified step. Finally, a computer simulation is conducted to demonstrate the dramatic performance improvement of the proposed algorithm.%矢量传感器可以同步共点地获取声场的标量和矢量信息，具有较好的指向性、紧凑的结构及抑制各向同性噪声干扰等优点，同时应用多个矢量传感器组成矢量阵可以获得更高的测量增益，为低信噪比条件下舰船辐射噪声量级的准确评价提供一种有效手段。本文建立矢量阵近场信号模型，给出基于单个矢量传感器输出量处理和基于阵列同类输出分量相乘处理的波束形成方法，并针对恒定束宽波束形成问题，提出一种基于 Kaiser窗的近场恒定束宽波束形成方法，利用 Kaiser窗的特点，通过设定窗函数的步长随指数变化，使设计波束响应逐渐趋于理想波束响应，提高了恒定束宽波束形成器的设计精度，最后通过仿真试验验证上述算法的性能。