A sidelobe suppression method for underwater acoustic imaging in presence of strong interferences

Our method uses the nonuniform element spacing array with aperture apodization. Section 1 of the full paper gives the mathematical derivation of our method; the equations needed for simulation are eqs. (3), (16), and (20). The aperture apodization seeks the optimal reception aperture to obtain the lowest sidelobe level of the two-way beam pattern. The simulation results, shown in Figs. 3, 5, and 6, indicate preliminarily that the maximum sidelobe level obtainable with nonuniform element spacing array with aperture apodization is much lower than that obtainable with uniform element spacing array only, at the small cost of a slight broadening of the mainlobe. We like to point out that our method is simple for operation.