基于FPGA的多波束实时动态聚焦波束形成方法

摘要

提高多波束测深系统的综合精度，不仅需要提高远场精度，近场精度也不可忽视。针对常规多波束测深系统中采用远场近似模型，使得近场精度急剧下降的不足，研究了基于FPGA的多波束实时动态聚焦波束形成（RT-DF-BF：Real-time Dynamic Focused Beam-forming）方法。该方法引入相移聚焦波束形成，论证其在多波束测深系统中解决近场问题的可行性，同时深入分析各个影响因素的实时处理情况，提出了一种基于FPGA的实时处理结构，该结构在输入通道为80个、采样率为28 kHz、波束数为128个的条件下完成RT-DFBF。水池实验结果验证了该方法的实时性、有效性和实用性，具有重要工程应用价值。%To increase the synthesized accuracy of a multi-beam sounding system not only requires to increase far-field accuracy,but also to raise near-field accuracy.Adopting a far-field approximation model in a multi-beam sounding system makes the near-field accuracy sharply drop.Here,the multi-beam real time dynamic focused beam-forming method was proposed based on FPGA.With the method the phase shifting focused beam-forming was introduced,and its feasibility to solve the near-field problem in a multi-beam sounding system was verified.Meanwhile,the real time processing of each influential factor was analyzed deaply,and a real time processing structure was proposed on the basis of FPGA.RT-DFBF in conditions of 80 input channels,sampling rate of 28kHz and 128 beams was completed with this structure.The pool test result testified the effectiveness and feasibility of the method.It was shown that the proposed method is valuable in engineering applications.