采用相位梯度自聚焦算法对非合作目标进行高分辨逆合成孔径雷达聚焦成像的处理过程中,回波多普勒偏置效应将严重影响后续转动补偿的效果,妨碍成像聚焦质量的提升。从相位梯度自聚焦算法的原理出发,阐释了多普勒偏置效应产生的原因。进而,分析了多普勒偏置效应对散射中心距离徙动补偿的影响。最后,提出了一种基于图像质量评价的多普勒偏置效应估计与补偿算法,并通过数值仿真分析和实测数据处理实验验证了本文分析结果的正确性。
When applying the phase gradient autofocusing (PGA) algorithm to high resolution inverse syn- thetic aperture radar (ISAR) imaging of non-cooperative targets, the byproduct of Doppler bias effect hampers the following rotational motion compensation process, and thus undermines the quality of the imaging result. This paper shows how Doppler bias effect appears in the PGA process from the perspective of the principle of PGA. Then, the paper illustrates how the Doppler bias effect affects the range migration compensation of scattering centers. Accordingly, an imaging quality evaluation based method for Doppler bias effect estimation and compensation is proposed. Finally, experiments with both numerical simulation and some real ISAR data are provided to illustrate the effectiveness of the proposed method.