基于宽带分裂阵列的水下远程被动多目标检测与定向

为获取更高的水下远程多目标检测和定向性能,基于工程中广泛应用的最小方差无畸变响应(MVDR)波束形成算法,设计了大间隔分裂线列阵,通过扩大阵列有效孔径改善了空间谱峰锐度。同时提出非相干宽带预处理方法,利用MVDR在多频子带下波束宽度和间隔的非一致性来抵消由于稀布阵元造成的栅瓣效应。最终实现大间隔分裂阵和宽带非相干波束形成的互补。仿真和湖上试验结果表明,与采用宽带MVDR的均匀线列阵和采用互相关法的大间隔分裂阵相比较,所提方法能显著提高对水下远程目标的检测和分辨性能。 

Long-distance underwater passive multi-target detection and direction finding based on the wideband split array

In order to obtain better performances of detection and direction finding of long distance multiple targets, the split linear array with large interval between the sub-arrays is designed based on the MVDR beam forming which is widely used in engineering.The application of extended array aperture improves the acutance of spatial spectrum peaks.On the other hand,the incorrelate signal method(ISM) wideband MVDR pre-processing algorithm has been presented.Because widths and intervals of grating lobes introduced by divided sub-arrays vary with sub-band,the corresponding ambiguous peaks are counteracted while incorrelate sub-band MVDR spectrums overlapped.Finally the processing results of sparse array and wideband ISM beam forming compensate each other.Computer simulation and the lake authentication show the scheme put forward can improve the detection and resolution performance to underwater targets compared with uniform linear array(ULA) applied wideband MVDR and split linear array applied cross-correlation.