Direct imaging of inhomogeneities in a 3D shallow ocean waveguide with an icecap

We are concerned with identifying scattering inhomogeneities in a three-dimensional shallow ocean waveguide with an icecap, which is motivated by applications in oceanic acoustics. A direct imaging method (DIM) is proposed to identify the marine point sources and medium obstacles from the near-field data. The key ingredient of the DIM is a certain imaging functional whose indicating behaviors is quantitatively characterized. Moreover, as corroborated by extensive numerical experiments, the DIM is computationally efficient and highly robust against noises, and the DIM can identify multiple sources and the scatterers of different shapes and scales from a few incidences and receivers. © 2023 Elsevier Inc.