Robust reconstruction of equivalent source method based near-field acoustic holography using an alternative...

Area of Science:

• Acoustics
• Signal Processing
• Computational Physics

Background:

• Near-field acoustic holography (NAH) is crucial for acoustic source identification.
• The equivalent source method (ESM) in NAH involves solving an ill-posed inverse problem to determine equivalent source strengths from measured pressure data.
• Traditional methods face challenges with accuracy and robustness, particularly concerning the hologram distance and transfer matrix properties.

Purpose of the Study:

• To develop a more robust and accurate method for acoustic field reconstruction using ESM-based NAH.
• To propose an explicit formula for calculating the regularization parameter in ESM-based NAH.
• To demonstrate the effectiveness of the proposed method under challenging conditions, such as increased hologram distances.

Main Methods:

• The study proposes an explicit formula for the regularization parameter in ESM-based NAH.
• The regularization parameter is defined as proportional to the product of the hologram distance and the maximum singular value of the transfer matrix.
• The method's performance is evaluated by reconstructing acoustic fields with varying hologram distances.

Main Results:

• The proposed approach yields robust acoustic field reconstruction.
• Effective reconstruction is achieved even when the hologram distance is up to 5 times larger than the average microphone spacing.
• The explicit formula for the regularization parameter enhances the stability and accuracy of the inverse problem solution.

Conclusions:

• The developed explicit formula offers a significant improvement for ESM-based NAH.
• The method provides a robust solution for acoustic field reconstruction, overcoming limitations of previous approaches related to hologram distance.
• This advancement has implications for improved acoustic imaging and source localization in various applications.