FFBP算法在合成孔径声纳成像中的应用

Application of FFBP algorithm to synthetic aperture sonar imaging

时域合成孔径成像算法可以更好地适应多子阵造成的方位向采样不均匀问题,并且具有存储空间小、并行处理方便的优点。但精确时域算法运算量非常大,快速分块反向传播投影(Fast Factorized Back Projection,FFBP)成像算法则可以大大降低成像计算量。详细分析了FFBP声程误差的距离效应、孔径合并策略和图像分裂策略、成像的计算量等关键问题,并给出了仿真和实测数据成像结果。通过对仿真和实测成像结果的分析表明:FFBP算法可以提高计算效率,适用于实时合成孔径声纳成像系统。

Time domain synthetic aperture imaging algorithm can adapt the non-uniform sampling on azimuth direction caused by multi-element arrays, and it has the advantages of lower memory demand and convenient for parallel processing. The computing load of the exact time domain algorithm is huge. However, using FFBP imaging method can reduce the computing load dramatically. Detailed analysis is made including the range effect of error, sub apertures combination and image factorizing strategy, and computing load of FFBP imaging algorithm. Simulation and real data results show that FFBP algorithm is a proper choice for real-time SAS system due to high computation efficiency and good quality of SAS imaging.