Publications

2026

1. 

   Using A Structured Beam to Enhance the Accuracy of Time-of-Flight Underwater Optical Ranging in Single-Beam Measurements

   Yuxiang Duan, Zixun Zhao, Heng Wu, Huibin Zhou, Zile Jiang, Andrew Bergey, Yingning Wang, Ruoyu Zeng, Yue Zuo, Wing Ko, Muralekrishnan Ramakrishnan, Luke Rumbaugh, Robert Bock, Moshe Tur, and Alan E. Willner

   Journal of Lightwave Technology, 2026

   DOI

2. 

   AMULET: Acoustic Metastructure for Direction-of-Arrival Estimation Underwater Using a Single Hydrophone

   Andrew Bergey, Nakul Garg, and Akshay Gadre

   In Proceedings of the 2026 ACM/IEEE International Conference on Embedded Artificial Intelligence and Sensing Systems, May 2026

   Best Demo Award SenSys ’26 Abs DOI Video Code Poster Slides

   Best Demo Award SenSys ’26

   Small autonomous underwater vehicles (AUVs) that can perceive and explore the environment at low cost are increasingly being deployed for seafloor mapping and biome sensing. A critical sensing ability that many of the larger submarines possess is to perform directional SONAR using arrays of hydrophones to map the environment. Unfortunately, this ability to identify direction-of-arrival (DoA) remains too inaccurate or even infeasible for the small AUVs due to size, weight, and power (SWaP) constraints. This paper presents a new opportunity in augmenting this critical ability using a single hydrophone. This paper presents AMULET, a single hydrophone direction-of-arrival sensing solution in underwater scenarios which leverages acoustic metastructures to introduce directional signatures in the received signal. AMULET’s metastructure takes inspiration from sea shells with a spiral shape that uses air-as-a-metamaterial to augment directional diversity. We further demonstrate how we can extract and compare these directional signatures to estimate the angle-of-arrival across signals of various modulation schemes and different bandwidths as well as complex multipath. Our evaluation in a real-world lake deployment demonstrates a mean error of 4.1° with robustness to distance, across environments, and signal-to-noise ratios.

2025

1. 

   Experimental Demonstration of Using Structured Light to Increase the Accuracy of Time-of-Flight Underwater Ranging in Single-Shot Measurements

   Yuxiang Duan, Zixun Zhao, Heng Wu, Huibin Zhou, Zile Jiang, Andrew Bergey, Yingning Wang, Ruoyu Zeng, Yue Zuo, Wing Ko, Muralekrishnan Ramakrishnan, Luke Rumbaugh, Robert Bock, Moshe Tur, and Alan E. Willner

   In CLEO 2025, 2025

   Abs DOI

   We experimentally demonstrate increased accuracy of time-of-flight underwater ranging using structured light. We show a reduction of average ranging error from \textgreater40 mm to \textless4 mm over 0-0.8m under scattering ( γ =2.3 m - 1 ) using the combined approach in single-shot measurements.

2023

1. 

   Underwater Time-of-Flight Camera for Remotely Operated Vehicle Applications

   Evelyn DeMember, Andrew Bergey, Caleb. Pipes, Nathaniel Stuyck, Luke Rumbaugh, and David Illig

   In OCEANS 2023 - MTS/IEEE U.S. Gulf Coast, Sep 2023

   2nd Place - Student Poster Competition DOI

   2nd Place - Student Poster Competition @IEEE/MTS OCEANS 2023