多接收阵合成孔径声呐CZT成像算法  

CZT algorithm for multiple-receiver synthetic aperture sonar

作　　者：马梦博[1] 唐劲松[1] 钟何平[1] 田振[1] MA Mengbo;TANG Jinsong;ZHONG Heping;TIAN Zhen(Naval Institute of Underwater Acoustic Technology,Naval University of Engineering,Wuhan 430033,China)

机构地区：[1]海军工程大学水声技术研究所

出　　处：《华中科技大学学报（自然科学版）》2019年第9期84-89,共6页Journal of Huazhong University of Science and Technology(Natural Science Edition)

基　　金：国家自然科学基金资助项目(61671461)

摘　　要：针对多接收阵合成孔径声呐(SAS)收发阵元是空间分开的,双根号之和形式的距离历程导致点目标二维谱解析表达式求解困难这一问题,在'非停走停'模式下建立了多接收阵合成孔径声呐距离历程模型,并采用级数反演的方法推导了点目标的精确二维谱.分析距离徙动后发现:可以通过近似将其变为斜距变量的线性函数,进而利用Chirp-z变换进行距离徙动校正,避免了插值处理,提高了算法效率,保证了相位保真度.仿真实验和实测数据测试验证了本文算法的优越性.Synthetic aperture sonar(SAS)is always composed of a linear array of receivers and a single transmitter,which leads to the fact that the range history is a double-square-root term,so it is difficult to acquire the analytical expression of the two-dimensional spectrum of the point target.In order to solve these problems,a range history geometry of multiple-receiver SAS in'nonstopand-hop'mode was established in this paper,and the two-dimensional spectrum of point target by using the method of series reversion was derived.After analyzing the range cell migration,it is found that it can be approximated as a linear function of slant range,then can be corrected by Chirp-z transform,which avoids the interpolation processing,so the efficiency is improved and the phase is preserved.Simulation data and real data verify the superiority of the algorithm.

关 键 词：合成孔径声呐 多接收阵 非停走停 级数反演 距离徙动校正 CHIRP-Z变换 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术] U666.7[自动化与计算机技术—计算机科学与技术]