基于稀疏布阵的实时三维成像声纳系统

水下实时三维成像声纳系统可以有效地提高对水下目标探测及识别的能力,本文提出基于稀疏面阵的实时三维成像声纳系统,该系统包括3个部分:窄带信号发射系统、稀疏布阵接收系统及信号处理系统。信号处理系统在远场情况下采用二维FFT波束形成获得目标三维成像,近场情况下采用自聚焦二维FFT波束形成获得三维成像结果。相比于直接相移波束形成,稀疏布阵情况下采用二维FFT波束形成算法具有更小的计算量和内存需求量的优势。基于该成像算法,设计并实现一套实时三维成像声纳系统,通过多次湖上及海上实验对该系统进行测试,实验结果表明:该系统可以获得水下近场及远场目标的三维图像并满足实时成像的要求。

Real time 3D acoustical imaging sonar system based on sparse planar array

Underwater real time 3D imaging sonar system can effectively improve the ability of underwater target detection and identification. In this paper, a real time 3D acoustical imaging sonar system based on sparse planar array is proposed. The system consists of three parts: a transmitter of narrowband excitation, a receiving sparse planar array, and a signal processing system. The signal processing system uses two dimensional fast Fourier transform (FFT) beamforming algorithm to process the acquired signals from a scene in the far field and obtain its 3D target image. Under near field condition, the signal processing system adopts auto focused 2D FFT beamforming method to obtain the 3D target image. Compared with the direct phase shift beamforming algorithm, the two dimensional FFT beamforming algorithm adopted under sparse planar array condition has the advantages of less computation burden and memory requirement. Based on the proposed imaging method, a real time 3D acoustical imaging sonar system was designed and developed, which has been extensively employed in lake and sea trials. The test results demonstrate that the system can obtain the 3D images of the scenes in far field and near field, and meet the real time imaging requirement of underwater target detection.