Beam-space high-resolution bearing estimation method for underwater physical array and its experimental studies

In order to reduce the negative effect for DOA estimation from strong interfering signals distributed over the sea surface, low-sidelobe is needed when multibeam is preformed in beam-space MUSIC. Due to array model mismatch between practical array manifold and ideal array manifold, expected sidelobe level can not be reached. Therefore, we present a new beam-space high resolution bearing estimation method. The method adopts adaptive beam optimization based on measured array manifold to design multibeam with low-sidelobe. The influence of array mismatch errors between ideal manifold and practical manifold can be effectively alleviated. Thus, expected low-sidelobe can be obtained in beampattern. Moreover, the method can be used for arbitrary geometry array. Anechoic tank experimental results show that better performance of direction estimation can be obtained with our method.