Blackmore Joseph, Cleveland Robin O, Mobley Joel
Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, United Kingdom.
Department of Physics and Astronomy, and National Center for Physical Acoustics, University of Mississippi, University, Mississippi, 38677, USA.
J Acoust Soc Am. 2018 Nov;144(5):2947. doi: 10.1121/1.5079637.
The angular spectrum method (ASM) is an effective tool for propagating wave fields between parallel planes through decomposition of the field into a series of independent plane waves. One source of error is interference from mirror sources introduced through the inherent periodicity of the fast Fourier transform (FFT) used to implement this method numerically. Here, spatial filters attenuate waves propagating at large angles, which are sensitive to mirror sources. Simulations show that this suppresses the ripple artifact whilst preserving the accuracy of the ASM-computed fields. To achieve comparable performance without filtering requires up to a 13.5-fold increase in computation time.
角谱法（ASM）是一种通过将场分解为一系列独立平面波在平行平面之间传播波场的有效工具。误差来源之一是通过用于数值实现该方法的快速傅里叶变换（FFT）的固有周期性引入的镜像源干扰。在这里，空间滤波器会衰减以大角度传播的波，这些波对镜像源敏感。模拟表明，这在保留ASM计算场准确性的同时抑制了波纹伪影。若不进行滤波要达到可比性能，则计算时间需要增加多达13.5倍。
