基于正交球面波插值的近场声全息分辨率增强方法

Resolution enhancement of nearfield acoustic holography by interpolation using orthogonal spherical wave sources

本文提出一种基于正交球面波插值的近场声全息图像分辨率增强方法。该方法按照Helmholtz方程确定的声学规律,通过若干不同阶次的球面波源叠加拟合实际声场,实现全息面声压插值,从而等效地增加全息面声压数据,减小测量间隔,在一定程度上恢复由于实际测量间隔太大而损失了的倏逝波信息,从而使近场声全息图像得到提高。数值仿真表明该方法可以有效提高近场声全息图像的分辨率。

To enhance the resolution of the nearfield acoustic holography image,a new method based on interpolation using orthogonal spherical wave source is proposed in this paper.According to the acoustic rule which is demonstrated by the Helmholtz equation,the interpolation for acoustic pressure is realized by superposing a series of spherical wave sources of deferent orders.So that,acoustic pressure data on hologram surface are increased equivalently,the sampling interval is reduced,information on evanescent waves which is lost because of large sampling interval is recovered,and the nearfield acoustic holography image is improved.Numerical simulation shows that the method can enhance the resolution of the nearfield acoustic holography image efficiently.