Super-resolution underwater acoustic imaging method based on optics-like synthetic aperture

Traditional underwater acoustic imaging techniques are constrained by the physical aperture of sonar systems and sampling conditions, making it challenging to overcome spatial resolution limitations on the order of wavelength. This paper proposes a super-resolution underwater acoustic imaging method based on optics-like synthetic aperture, which significantly enhances imaging resolution through multi-angle overlapping scanning and iterative reconstruction in the frequency-spatial domain. By rotating a compact sonar array to acquire partially overlapped sectorial sub-aperture data, the method integrates sparsely sampled wavenumber spectrum information into a high-density spectral distribution via redundancy-constrained phase retrieval. Simulation results demonstrate that under a scanning configuration of 36 azimuthal angles (50% overlap), the Structural Similarity Index (SSIM) of the iteratively reconstructed image reaches 0.9377. The proposed approach provides a novel technical pathway for high-precision underwater target detection.