基于空间平滑的多波束测深声呐相干分布源方位估计

在多波束测深声呐的工作环境中，若海底反向散射信号不满足点源假设，方位估计精度将严重下降，而基于分布源模型的方位估计算法可以适应这种环境。目前，大多数分布源算法要求分布源之间不相干，有人提出采用Toeplitz方法估计相干分布源，但该方法精度不高并且忽略了角度扩展参数。为解决多波束测深声呐相干分布源的方位估计问题，提出了基于空间平滑的广义MUSIC方法，公式推导证明了算法的有效性，通过计算机仿真给出算法方位估计的精度以及不同信噪比条件下的性能，最后采用多波束测深系统的实验数据对算法进行了验证。

DOA estimation based on spatial smoothing for multi-beam bathymetric sonar coherent distributed sources

In some multi-beam bathymetric sonar applications, accuracy of the DOA estimation algorithms presently used reduces for the seafloor backscattering signals dissatisfying the point sources assumption, while the DOA estimation algorithms based on assumption of distributed source model have a potential to solve it well. However, most existing distributed source algorithms fail to distinguish incoherent sources apart. Although Toeplitz method has been proposed and tested effective to the problem, it has low estimation accuracy and can’t estimate the parameters of angle expansion. Aiming at the DOA estimation problem of multi-beam bathymetric sonar, a generalized MUSIC algorithm based on spatial smoothing is proposed and proved to be effective by formula derivation. Its accuracy and performances under different SNR are given via computer simulation. Finally, the method is tested with experimental data of multi-beam bathymetric sonar.