一种改进的基于FrFT的SAR运动目标检测与成像方法

A Modified Method of SAR Moving Target Detection and Imaging Based on Fractional Fourier Transform

针对传统的基于FrFT的SAR地面运动目标检测方法的不足,该文结合分数阶Fourier域滤波、重排谱图以及CLEAN思想,提出了一种改进的方法。该方法能够以较高精度估计目标的多普勒起始频率和中心频率,并能分辨在时频平面位于同一直线的多个目标。最后给出了FrFT数值计算结果与有量纲的多普勒参数之间的转换公式。仿真结果表明了该方法的有效性。

To overcome the shortcomings of the conventional method of SAR moving target detection and imaging based on the Fractional Fourier Transform（FrFT）, a modified method, which combines filtering in fractional Fourier domain, reassigned spectrogram and CLEAN, is presented for the detection, parameter estimation and imaging of moving targets. This method is able to estimate precisely the initial Doppler frequency and the Doppler centroid, and to distinguish between multiple targets lying in the same line in the time-frequency plane. The transform formulas between FrFT numeral results and Doppler parameters are also given in the paper. Simulated results prove the validity of the approach.