一种基于相干积累CPF和NUFFT的机动目标ISAR成像新方法

发布时间：2018-05-11 21:15

本文选题：逆合成孔径雷达 + 机动目标　；参考：《电子学报》2017年09期

【摘要】：机动目标的复杂运动导致散射体回波信号多普勒频率时变,给逆合成孔径雷达(ISAR)成像方位向处理带来困难.而传统的距离-多普勒(RD)成像方法、Wigner-Ville distribution(WVD)瞬时成像方法、Radon-Wigner等成像方法由于成像效果差或运算效率低等因素,不适合复杂运动目标的ISAR实时成像.针对这些问题,本文提出了一种基于相干积累三次相位函数(CPF)的机动目标ISAR成像新方法.首先,把平动补偿后的各距离单元数据,通过CPF变换到时间-调频率平面.然后,利用各散射体自项能量平行于时间轴分布特性,提出一种基于相干积累的交叉项和虚假伪峰抑制方法,进而得到各散射体在频率-调频率平面的高分辨分布特性.最后,通过向频率轴上的投影得到该距离单元目标的方位ISAR图像,并通过引入非均匀快速傅立叶变换(NUFFT)来降低算法计算复杂度.计算机仿真处理结果验证了该方法的有效性.
[Abstract]:The complex motion of maneuvering target causes the Doppler frequency of scattering echo signal to be time-varying, which makes it difficult to process the inverse synthetic aperture radar (ISAR) imaging azimuth direction. However, the traditional range-Doppler ISAR imaging method is not suitable for real-time ISAR imaging of complex moving targets because of the poor imaging effect and low computational efficiency, such as Radon-Wigner imaging method, which is the instantaneous imaging method of Wigner-Ville distribution. In order to solve these problems, a new method of maneuvering target ISAR imaging based on coherent integration cubic phase function (CPF) is proposed in this paper. First, the distance unit data after the translation compensation is transformed to the time-frequency plane by CPF. Then, based on the distribution of energy of each scatterer parallel to the time axis, a cross-term and false pseudo-peak suppression method based on coherent accumulation is proposed, and the high-resolution distribution characteristics of each scatterer in the frequency-modulated frequency plane are obtained. Finally, the azimuth ISAR image of the distance element target is obtained by projecting to the frequency axis, and the computational complexity is reduced by introducing the nonuniform fast Fourier transform (FFT). The effectiveness of the method is verified by computer simulation.
【作者单位】：重庆大学飞行器测控与通信教育部重点实验室;西北工业大学电子信息学院;
【基金】：国家自然科学基金(No.61501068,No.61301120,No.51377179) 重庆市前沿与应用基础研究计划(No.CSTC2015jcyj A40001) 中央高校基金(No.106112015CDJXY500001)
【分类号】：TN957.52

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