A review on underwater beamforming: Techniques, challenges, and future directions

This paper comprehensively reviews recent advancements in Underwater Beamforming (UWB) systems, highlighting its pivotal role in underwater communication, sensing, and environmental monitoring. It explores the various beamforming applications, ranging from maritime surveillance to marine life monitoring, and indicates its significance in enhancing signal clarity, spatial resolution, and noise suppression in underwater acoustic environments. The unique challenges posed by the underwater environment that introduce complexities into the beamforming process such as non-stationary noise interference, severe signal attenuation, multipath propagation, and dynamic environmental variability are thoroughly discussed. The review systematically discusses and examines conventional, adaptive, and learning-based beamforming techniques, analyzing their strengths, limitations, and suitability for various underwater conditions. A detailed analysis of Direction of Arrival (DOA) estimation methods is provided. Furthermore, the review surveys the metrics commonly used to assess the performance of beamforming algorithms and compares their performance numerically. Emerging trends in beamforming, particularly the integration of data-driven machine learning approaches with traditional signal processing methods, are also discussed. The paper concludes by highlighting critical gaps in existing research and proposing future directions. • The field of beamforming has been well-reviewed in terrestrial domains, such as radar and wireless communications. However, there has been no comprehensive review in the whole literature body that surveyed underwater beamforming. This study fills that gap by examining how beamforming techniques are applied and optimized in underwater environments. Therefore, this study is the first of its kind to provide a unique and holistic perspective on underwater beamforming by covering two distinct yet related areas: Underwater sensing and communication. • This comprehensive review highlights the advancements, critical challenges associated with underwater beamforming techniques and future research directions for the research community. • We believe this work contributes significantly to understanding the current landscape of underwater beamforming research and identifies pivotal areas for future exploration. • Given the journal’s focus on ocean engineering applications and acoustic technologies, we are confident that this work aligns well with its objectives and will interest the readership. We have ensured that the manuscript adheres to the journal’s guidelines and is free of any conflicts of interest.