由于连续波合成孔径雷达(synthetic aperture radar,SAR)特有的工作方式,带来了不同的回波信号形式。首先分析了调频连续波(frequency modulated continuous wave,FMCW)SAR动目标回波信号模型,然后在补偿连续波SAR与脉冲式SAR不一致性的基础上,提出了一种基于Chirp-Z变换校正动目标回波包络距离弯曲,Radon变换校正剩余距离走动,改进的离散Chirp傅里叶变换(modified discrete Chirp Fourier transform,M-DCFT)搜索参数的新方法,动目标仿真数据处理验证了该方法参数估计的准确性和有效性。另外根据估计的参数对动目标成像取得了良好的聚焦效果。
The received signal model of ground moving targets is analyzed firstly in frequency modulated continuous wave(FMCW)synthetic aperture radar(SAR),which has different forms due to the particular working mode of continuous wave SAR.Then based on the compensation of the discrepancy between continuous wave SAR and pulse SAR,a new method is proposed for ground moving target parameter estimation,which uses a Chirp-Z transform for range curvature correction,Radon transform for residual range walk correction, and modified discrete Chirp Fourier transform(M-DCFT)for parameters search.Simulation data processing for ground moving targets validates the proposed approach.Furthermore,the moving targets are well focused according to the estimated parameters.