使用合成滤波器组的SAS方位向非均匀采样信号重构
Reconstruction of non-uniformly sampled signals of synthetic aperture sonar by synthetic filter bank
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摘要: 针对多子阵合成孔径声纳(Synthetic Aperture Sonar,SAS)在方位向上非均匀采样对后续成像处理带来的方位向失真的影响,给出了基于滤波器组的方位向非均匀采样信号重构算法。该算法利用SAS方位向周期性非均匀采样信号与经过分析滤波器组的信号之间的相似性,将周期非均匀采样信号通过合成滤波器组进行重构得到均匀采样信号。该算法相对于传统时域重构和频域重构方法,具有点目标冲激响应主瓣宽度更窄,旁瓣电平更低的优点。通过仿真与对湖试数据的处理,该算法在多子阵SAS上的有效性与优势得到验证。Abstract: Non-uniform azimuthal sampling of multiple receiver Synthetic Aperture Sonar(SAS) will cause distortion of the latter imaging in the azimuth direction.A method of using filter bank to reconstruct the non-uniform samples is given in this article.This method turns the non-uniform samples into the uniform samples by the synthetic filters in virtue of the similarity between the non-uniformly samples of SAS and the signals after a decomposing filter.Compared with the traditional time-region and frequency-region reconstruction methods,this algorithm has the advantage in obtaining both a narrower main-lobe and lower side-lobes in the impulse response of point target.The effectiveness and the advantages of applying this algorithm to Multiple Receiver SAS are verified by simulation and the data from lake experiments.