Cigada Alfredo, Lurati Massimiliano, Ripamonti Francesco, Vanali Marcello
Mechanical Engineering Department, Politecnico di Milano, Milano, Italy.
J Acoust Soc Am. 2008 Dec;124(6):3648-3658. doi: 10.1121/1.2998778.
This paper introduces a measurement technique aimed at reducing or possibly eliminating the spatial aliasing problem in the beamforming technique. Beamforming main disadvantages are a poor spatial resolution, at low frequency, and the spatial aliasing problem, at higher frequency, leading to the identification of false sources. The idea is to move the microphone array during the measurement operation. In this paper, the proposed approach is theoretically and numerically investigated by means of simple sound propagation models, proving its efficiency in reducing the spatial aliasing. A number of different array configurations are numerically investigated together with the most important parameters governing this measurement technique. A set of numerical results concerning the case of a planar rotating array is shown, together with a first experimental validation of the method.
本文介绍了一种测量技术，旨在减少或可能消除波束形成技术中的空间混叠问题。波束形成的主要缺点是在低频时空间分辨率较差，而在高频时存在空间混叠问题，这会导致识别出虚假声源。其思路是在测量操作过程中移动麦克风阵列。本文通过简单的声音传播模型对所提出的方法进行了理论和数值研究，证明了其在减少空间混叠方面的有效性。对多种不同的阵列配置以及控制该测量技术的最重要参数进行了数值研究。展示了一组关于平面旋转阵列情况的数值结果，以及该方法的首次实验验证。
