线阵分裂波束处理技术在水声探测中的应用

Application of split-beam processing of line array in underwater acoustic detection

声呐波束形成处理通常输出各个方位上的目标能量信息,利用指向性极大值位置给出目标的大致方位。为了得到更加精确的目标方位估计,需要寻找对目标方位微小变化作出灵敏反应的物理量。分裂波束处理所输出的各个方位二子阵的相位差信息,对方位变化十分灵敏,其测向精度接近于克拉美罗下界,不需增加太大运算量即可显著提高声呐系统测向精度,在水声中得到了广泛研究和应用。对线阵分裂波束处理在水声探测中不同的应用进行了梳理和总结,重点阐述了基于分裂阵半波束处理的被动声呐宽带相关检测、主动声呐相位单元化处理、超波束形成和水下慢速目标相位差空时方差自动检测跟踪(Automatic Detection and Tracking,ADT)技术的原理、处理流程和结果。

The outputs of sonar beamformer represent the target power information in all directions and the peak position of directivity is used as the target＇s approximate azimuth. It is necessary to find an appropriate parameter, which is sensitive to the tiny change of azimuth, to obtain accurate target＇s azimuth. The phase difference in every azimuth given by two sub array can be used to estimate the azimuth close to Cramer-Rao low boundary, and the accuracy of direction finding of sonar system can be obviously improved without much operation. So far the half beam processing technique of split-array has been widely researched and applied. The different applications of this technique in underwater acoustics equipment, such as the wideband cross-correlation detection in passive sonar, phase binning processing in active sonar,HBF and ADT with variance of phase difference, are mainly discussed and summarized in this paper with principles, processing flows and results.