一种提高分裂阵频域波束形成测向分辨力的方法

为了提高声呐系统对目标方位的分辨能力，本文提出一种分裂阵频域波束形成方法，即超波束互谱测向法。通过将超波束方法得到的方位谱加权到互谱方法得到的波束形成结果上，从而得到最终的波束输出结果。超波束互谱测向方法的优点是既能够降低主瓣宽度，抑制旁瓣，提高测向分辨力；又能够保留相位信息，为后续谱分析应用提供参考。实验室水池测试结果表明，利用阵元间距为0.016 m的16元均匀直线阵，对于37.5 kHz的声信号，采用超波束互谱方法进行波束形成与单纯采用互谱方法进行波束形成相比较，在0°和60°方位上的波束主瓣宽度分别减小了3.8°和6.9°，旁瓣幅度降低超过30 dB，测向分辨力得到明显提高，从而验证采用超波束互谱测向方法提高测向分辨力的可行性和有效性。

A method for improving the direction finding resolution of split array beam forming in frequency domain

To improve the direction finding resolution of the target bearing of the sonar system, a beam formingmeth-od of split array in frequency domain, namely the hyper beam & cross spectrum direction finding method is presented in this paper. The final beam forming output is obtained by way of weighting the bearing spectrum of the hyper beam to the cross spectrum. The advantages of this new method are to reduce the width of the main lobe, suppress the side lobe and keep the phase information. The experimental results show that the hyper beam & cross spectrum method can respectively achieve beam width decrease of 3.8° and 6.9° and side lode suppression of more than 30 dB at angles of 0° and 60° in compassion with the cross spectrum method under the condition that the distance of the 16 element uniform linear array is 0.016m and the frequency of the sound source is 37.5 kHz. The feasibility and availability of the new method for improving the direction finding resolution are verified.