成像声呐中聚焦波束形成技术研究及实现

介绍了聚焦波束形成的基本原理,分析了一种基于半圆阵的相位补偿方法。通过Matlab仿真得出聚焦波束形成的波束图,相比远场方法,波束宽度减小,旁瓣得到抑制。设计了一种基于FPGA的数字聚焦波束形成器的实时处理结构,使用8组加权系数即可完成成像声呐近场范围内分辨力的改进。通过乒乓操作和并行结构提高处理速度,实时产生72个波束。实验结果表明,所设计的聚焦波束形成器使某型成像声呐近场分辨力得到了提高。

Focused beam-forming technique and implementation of imaging sonar

This paper introduces the principle of focused beam-forming in near-field, and analyses the method of phase compensation for a semicircle array. The beam pattern of focused beam-forming has been obtained by matlab simulation. Compared with the beam pattern of conventional methods, the beam width is shaped and the sidelobe is decreased. A real time processing structure of digital focusing beamformer is designed based on FPGA, in which eight sets of weight coefficients are used to achieve the improvement of resolution in the near-field environment. The processing speed is increased and 72 beams are generated in real time through ping-pong option and parallel structure. The experimental results testify that the focusing beamformer designed in this paper makes a great improvement in near-field resolution of the imaging sonar.