基于分组时延预处理的时域波束形成方法

Time domain beam-forming algorithm based on sub-group & time delay preprocessing

对于不等强度多目标情况下的弱目标检测问题,依据波束形成归一化指向性函数在目标方向上输出值为1、在非目标方向上输出值为小于1的特性,提出一种基于分组时延预处理的时域波束形成方法。该方法首先对线列阵接收数据进行分组处理;然后,按搜索角度对各组数据进行时延预处理,并对各组预处理结果进行相加,得到一组新数据;最后,对该组新数据按时域波束形成进行处理,得到该搜索角度对应波束值。理论推导、数值仿真和试验数据处理结果均表明:相比常规时域波束形成,该方法所得波束形成指向性函数发生了变化,旁瓣级得到了13dB以上的改善,降低了强目标旁瓣级对弱目标检测的影响。

For the problem of weak targets detection under the condition of multiple targets, according to the feature of the value of normalized directivity function being 1 on target direct and being less than 1 on non-target direct, a time domain beam-forming method based on sub-group & time delay preprocessing was proposed. Firstly, makes sub-group preprocessing for linear array receiving data. Then, does time delay pretreatment for the data of sub-group on the search angle, accumulates the results of time delay pretreatment and obtains a new set of data. Lastly, obtains the beam value of the search angle by time delay beam-forming. The theoretical analysis, numerical simulation and experimental results show that, compared with conventional beam-forming, the directivity function of this method has changed, the side-lobe level is improved more than 13 dB, reduces the impact of side-lobe level on weak targets detection.