| 时域压缩合成孔径超分辨水声成像算法 |
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| 引用本文： | 罗俊杰,迟骋,张春华,刘纪元,王朋,黄海宁.时域压缩合成孔径超分辨水声成像算法[J].声学学报,2021,46(6):1144-1152. |
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| 作者姓名： | 罗俊杰 迟骋 张春华 刘纪元 王朋 黄海宁 |
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| 作者单位： | 1. 中国科学院声学研究所 北京 100190; |
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| 基金项目： | 中国科学院声学研究所青年英才计划项目(QNYC201728)资助国家自然科学基金项目(11504402) |
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| 摘 要： | 提出一种针对水下稀疏目标的时域压缩合成孔径声呐成像方法(TC-SAS),实现了水声目标高分辨实时成像。通过多子阵的孔径合成,在时域上构造出成像网格格点到有效孔径内逐帧阵列的格林函数,并给出成像区域散射强度到数据域的映射矩阵;然后利用该区域空域稀疏的先验知识,通过正交匹配追踪的稀疏重构方式,解算出成像区域散射系数矩阵,实现了稀疏目标高分辨成像.同时,针对线性调频信号提出数据缩减的方法,通过对观测数据和字典矩阵同时脉压后截取,减小了数据规模;进一步结合二维矩阵数表查表的方法,以空间换时间,实现了区块实时成像。数值仿真以及湖试试验表明,所提算法能分辨出传统的时延求和算法难以分辨的目标,并且在图像清晰度指标上平均提升4.9 dB.改善了合成孔径声呐的成像质量.
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| 关 键 词： | 压缩感知 超分辨成像 合成孔径声呐 数据缩减 二维矩阵数表 |
| 收稿时间： | 2020-10-18 |
Timedomain compressive synthetic aperture super-resolution underwater acoustic imaging algorithm |
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| Affiliation: | 1. Institute of Acoustics, Chinese Academy of Sciences, Beijing 100190;2. Key Laboratory of Science and Technology on Advanced Underwater Acoustic Signal Processing, Chinese Academy of Sciences, Beijing 100190;3. University of Chinese Academy of Sciences, Beijing 100049 |
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| Abstract: | A Time domain Compressive Synthetic Aperture Sonar imaging method(TC-SAS) for underwater sparse targets is proposed,which achieves high-resolution real-time imaging of underwater acoustic targets.Through the aperture synthesis of multiple subarrays,the Green's function from the imaging grid point to the frame by frame array within the effective aperture is constructed in the time domain,and the mapping matrix from the scattering intensity of the imaging area to the data domain is given.Then,using the prior knowledge of spatial sparsity of the area,the scattering coefficient matrix of the imaging area is obtained by the sparse reconstruction method of orthogonal matching pursuit,and the sparse target high-resolution imaging is realized.At the same time,a data reduction method is proposed for Linear Frequency Modulation(LFM) signal,which reduces the data scale by intercepting the observation data and dictionary matrix after pulse compression at the same time;furthermore,combining with the method of looking up the two-dimensional matrix table,the real-time imaging of the block is realized by exchanging space for time.Numerical simulation and lake experiments show that the proposed algorithm can distinguish the target which is difficult to be distinguished by the traditional time delay summation algorithm,and the image clarity index is improved by 4.9 dB on average,which improves the imaging quality of synthetic aperture sonar. |
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