Abstract:Towed array sonar is widely used in underwater target detection. During ship platform maneuvering, the towed array shape is distorted, deviating from linear configuration. This results in unknown array elements positions and steering vector mismatch, leading to significant performance degradation of the sonar. To solve this problem, the Shape and Azimuth estimation algorithm based on Sparse Bayesian Learning was proposed. The algorithm estimates target azimuth solely using received acoustic data, and the distorted array shape during maneuvering is modeled as a parabolic curve, with the parabolic curve, with the parabolic parameters treated as hyper-parameters in the SBL framework, enabling simultaneous estimation of both array shape parameters and target DOAs. Simulation results demonstrate that under the assumption of parabolic distortion model, the proposed algorithm achieves concurrent estimation of array distortion and target azimuths, exhibiting enhanced target detection capability and superior resolution.