Thinned Array Design With Minimum Number of Transducers for Multibeam Imaging Sonar

Abstract

A large number of transducers employed in the multibeam imaging sonar array significantly increases the hardware complexity, costs, and computational load. Although a great amount of work has been done to minimize the number of transducers in the array, one can verify that these methods do not provide optimal results when applied to the case of multiple beams. In this paper, a novel thinning method is proposed for multiple-beam conditions where the number of transducers is minimized by an iterative process. Optimal common transducers’ positions are selected by a wind-driven optimization (WDO) algorithm, and transducers’ weights are optimized by convex optimization in order to suppress the peak sidelobe level (PSLL). The performance of the proposed method is evaluated via simulations and experiments. Results show that the method is applicable to the minimization of the number of transducers under hundreds of beam conditions, and consequently reduces the complexity of the imaging sonar system with imaging performance still acceptable.