Array signal processing methods for achieving super-resolution using vortex waves

• Published in: The Journal of the Acoustical Society of America Vol. 146; no. 4; p. 2928
• Main Authors: Young, Andrew, Guild, Matthew D., Rogers, Jeffrey S.
• Format: Journal Article
• Language: English
• Published: 01-10-2019
• ISSN: 0001-4966; 1520-8524
• DOI: 10.1121/1.5137170

Helicoidal (vortex) acoustic waves have received much interest lately and can be generated by a variety of means, such as applying a prescribed phase shift to the elements of conventional 2-D planar arrays or by employing a leaky wave antenna in a circular arrangement. In the context of array signal processing, the beampattern associated with vortex wave generation has a strong central null that can be exploited to achieve far field super-resolution in a variety of applications. Although recent physical acoustics research into vortex waves has focused on active applications such as particle manipulation or propagating sub-diffraction-limit features into the far field, vortex waves can also be utilized in passive applications such as source localization. This work investigates the signal processing implications of using vortex waves in both active and passive regimes. Key trade-offs between conventional, adaptive, and vortex-wave-based array signal processing methods are examined by simulating a variety of array geometries and source/target configurations. Results indicate the potential for vortex wave methods to provide performance improvements over conventional and adaptive methods such as MVDR (minimum variance distortionless response) and MUSIC (multiple signal classification) in snapshot-deficient and high-bearing-rate target scenarios.