FMCW SAR快速运动目标检测与成像

调频连续波(frequency modulated continuous wave,FMCW)合成孔径雷达(synthetic aperture radar,SAR)特有的工作模式使得其回波信号相对脉冲SAR具有不同的形式。推导了FMCW SAR系统下运动目标的回波模型。提出了一种基于Hough变换的快速运动目标检测方法和Hough变换与分数阶傅里叶变换(fractional Fourier transform,FrFT)变换相结合的运动目标参数估计方法;利用该方法补偿FMCW系统引入的附加距离走动后,运动目标的成像效果明显提高。多点运动目标仿真数据处理验证了该方法对目标检测与成像的准确性和有效性。

Detection and Imaging of Fast Moving Targets via FMCW SAR

The received signal model of fast ground moving targets is established firstly in frequency modulated continuous wave (FMCW) synthetic aperture radar (SAR), which is different from that of pulse SAR due to the unique working scheme of FMCW. The impact of Doppler ambiguity induced by fast radial velocity of a moving target is analyzed in detail, and a novel algorithm based on Hough transform is proposed to detect fast moving targets which are covered by the clutter. Doppler ambiguity also lead to error in radial velocity estimation, thus in this paper, the estimation result of Hough transform is used to give an accurate parameter estimation with fractional Fourier transform (FrFT). The effectiveness of the proposed algorithm is validated by multi-point simulated data.