🤖 AI Summary
Increasing maritime traffic along coastlines exacerbates underwater radiated noise, threatening marine ecosystems. Method: This paper proposes a physics-guided probabilistic surrogate model to construct an underwater noise digital twin for three-dimensional transmission loss (TL) prediction. It integrates a learnable physics-informed mean function, terrain- and coordinate-aware neural encoders, a residual stochastic process, sparse variational Gaussian processes, and deep sigma-point processes—trained on large-scale synthetic data generated by a spherical-expansion–frequency-dependent absorption physical model and a Gaussian beam solver, enabling uncertainty-calibrated, efficient acoustic field modeling. Contribution/Results: The approach achieves, for the first time, real-time, seasonally adaptive, broadband 3D TL prediction, supporting worst-case scenario analysis, exposure boundary modeling, and noise impact assessment. Validated in the Salish Sea, it successfully informed vessel speed optimization strategies, significantly reducing acoustic impacts on marine mammals.
📝 Abstract
Ship traffic is an increasing source of underwater radiated noise in coastal waters, motivating real-time digital twins of ocean acoustics for operational noise mitigation. We present a physics-guided probabilistic framework to predict three-dimensional transmission loss in realistic ocean environments. As a case study, we consider the Salish Sea along shipping routes from the Pacific Ocean to the Port of Vancouver. A dataset of over 30 million source-receiver pairs was generated with a Gaussian beam solver across seasonal sound speed profiles and one-third-octave frequency bands spanning 12.5 Hz to 8 kHz. We first assess sparse variational Gaussian processes (SVGP) and then incorporate physics-based mean functions combining spherical spreading with frequency-dependent absorption. To capture nonlinear effects, we examine deep sigma-point processes and stochastic variational deep kernel learning. The final framework integrates four components: (i) a learnable physics-informed mean that represents dominant propagation trends, (ii) a convolutional encoder for bathymetry along the source-receiver track, (iii) a neural encoder for source, receiver, and frequency coordinates, and (iv) a residual SVGP layer that provides calibrated predictive uncertainty. This probabilistic digital twin facilitates the construction of sound-exposure bounds and worst-case scenarios for received levels. We further demonstrate the application of the framework to ship speed optimization, where predicted transmission loss combined with near-field source models provides sound exposure level estimates for minimizing acoustic impacts on marine mammals. The proposed framework advances uncertainty-aware digital twins for ocean acoustics and illustrates how physics-guided machine learning can support sustainable maritime operations.