基于分数傅立叶变换的SAR成像算法研究

当距离徙动较小时,合成孔径雷达(SAR)回波信号在方位向和距离向都可以转化为调频信号,据此提出一种基于分数傅立叶变换(FRFT)的SAR成像算法,通过距离向和方位向的特定阶次的FRFT,在两个方向上把回波信号同时近似地压缩为脉冲函数。理论分析和仿真数据结果表明,该算法计算简单快速,只需两次FRFT即在分数傅立叶域可以有效成像,并且成像精度优于传统的Chirp Scaling算法。

SAR Imaging Algorithm Based on Fractional Fourier Transform

In this paper,we bring forward a new fractional Fourier transform(FRFT) based SAR imaging algorithm.Because the echo signal of the Synthetic Aperture Radar(SAR) can be turn to chirp signal in both the range and azimuth direction,through the optimal-order FRFT on the SAR echo signal in both directions,we can compress the echo into just about an impulse function in both directions simultaneously.Theory analysis and computer simulation approve the efficiency of the method.It takes only two steps for imaging in the fractional Fourier domain,so this method is very simple and fast.The accuracy of the this method is much better than the chirp scaling algorithm(CSA).