Very low frequency three-dimensional beamforming for a miniaturized aperture acoustic vector sensor array.

Area of Science:

• Acoustics
• Signal Processing
• Array Signal Processing

Background:

• Miniaturized acoustic vector sensor (AVS) arrays are crucial for underwater acoustics.
• Traditional beamforming methods face limitations in achieving high gain and white noise gain simultaneously.

Purpose of the Study:

• To propose a novel three-dimensional (3D) beamforming method for miniaturized AVS arrays.
• To improve array gain and white noise gain compared to existing methods.

Main Methods:

• Extracting multipole modes using the AVS array.
• Synthesizing beam patterns based on the relationship between multipole modes and spherical harmonics.
• Validating the method through experimental results at very low frequencies.

Main Results:

• The proposed method achieves comparable array gain to spherical harmonics decomposition.
• The method demonstrates higher white noise gain under specific element spacing and wavelength conditions (0.01≤d/λ≤0.2).
• Experimental validation confirms the method's effectiveness at very low frequencies.

Conclusions:

• The developed 3D beamforming method offers superior white noise gain for miniaturized AVS arrays.
• This approach is particularly effective for low-frequency acoustic applications.
• The method provides a viable alternative for enhancing acoustic array performance.