Methods for determining infrasound phase velocity direction with an array of line sensors

Area of Science:

• Geophysics
• Acoustics
• Array Signal Processing

Background:

• Traditional infrasound arrays use multiple microbarometers to estimate signal direction via time separations.
• Directional resolution in microbarometer arrays is limited by noise and sensor count.
• Existing methods require significant space, especially for high-resolution measurements.

Purpose of the Study:

• To evaluate an alternative infrasound array design using directional line sensors.
• To compare the performance of line sensor arrays with traditional microbarometer arrays for phase velocity direction estimation.
• To assess the effectiveness of specific beamforming and deconvolution techniques for line sensor data.

Main Methods:

• Development and testing of an array of directional line sensors.
• Utilizing the instrument's orientation-dependent response to signal wavefronts.
• Evaluation of three beamforming techniques and one array deconvolution method.

Main Results:

• Line sensor arrays demonstrate directional resolution comparable to larger aperture microbarometer arrays.
• Real and synthetic data confirm the efficacy of exploiting spectral properties of line sensors.
• An array of five radial line sensors provides effective directional resolution in a smaller footprint.

Conclusions:

• Directional line sensors offer a viable and more compact alternative to traditional microbarometer arrays for infrasound monitoring.
• The proposed line sensor array design achieves high directional resolution with reduced spatial requirements.
• This approach enhances the feasibility of deploying high-performance infrasound arrays in space-constrained environments.