Multibeam side-look sonar system grating side lobe reduction technique

Abstract

A multibeam side-look sonar system includes a projecting transducer that projects a beam of acoustic energy to insonify a target area and a receiving transducer having a plurality of transducer elements arranged in a linear array. Each of the transducer elements generates a beam signal in response to acoustic energy reflected from the target area. A beamforming circuit, coupled to the receiving transducer, processes the beam signals generated by the transducer elements to form a beam pattern. The beam pattern for an end beam on the receiving transducer has a main lobe and grating side lobes. One of the grating side lobes may be insonified by the projected beam of acoustic energy. A shading circuit, coupled between the receiving transducer and the beamforming circuit, amplifies the beam signals with respective gains, and adjusts each of the respective gains to reduce an amplitude level of the grating side lobe insonified by the projected beam of acoustic energy.

Dependencies are inferred from the claim text.