Beampattern optimization based on predicted array manifold

A method for obtaining the array manifold in sensor array beampattern optimization is proposed in this paper. The proposed method is based on sound field prediction, using software packages ANSYS and SYSNOISE to simulate the process of measuring the array manifold in practical systems. For a given array supporting structure, the numerical boundary element method is used to calculate the array outputs when a test signal is assumed in the far-field of the array so as to obtain the sensor responses including both amplitude and phase of each element. Varying the relative incident angle of the test signal to the array will yield a collection of array responses in different directions and therefore form the array manifold. SYSNOISE provides a powerful tool to implement the idea of predicting the sensor responses. Since SYSNOISE itself does not possess the ability to generate the boundary grids, the finite element software ANSYS is used to fulfill it. A 14-element uniform arc array was constructed and tested in an anechoic watertank. Beampatterns based on the measured array manifold and that predicted shown very good consistence.