基于DPCA-FrFT的三通道SAR-GMTI方法

摘要

提出了一种新的基于DPCA-FrT的三通道SAR-GMTI方法,既可工作在原始数据域,又可工作在图像域.该算法以DPCA信号的chirp特征为基础,引入分数阶傅里叶变换,可同时估计出运动目标的位置、速度和径向加速度,实现了运动目标参数的全面、准确描述.当工作在原始数据域时,再利用方位向FrFT得到GMTI图像;而工作在图像域时,根据估计出的运动目标参数校正相位误差即可得到GMTI图像.所提方法有效地发挥了FrFT优良的抗噪性能和DPCA稳健的杂波对消能力,能够获得不同杂波环境、不同SNR条件下的精确的SAR-GMTI图像.仿真实验结果证明了所提方法的有效性.%A new multi-channel SAR-GMTI algorithm based on DPCA-FrFT is proposed, which can work on raw data and SAR image. According to the chirp characteristic of DPCA signal, we introduce the FrFT to detect the moving target and estimate the position, velocity and radial acceleration of the moving target, which lead to an overall and accurate description on motion parameters.Then according to the parameters, we apply the FrFT to compress the raw data on azimuth direction,or repositioning and focusing the moving target in the original SAR image.The proposed approaches take the full advantage of the excellent antinoise a-bility of the FrFT and ideal clutter cancellation of DPCA technique, and an exact SAR-GMTI image can be acquired in a clutter-rich and low SNR environment. The results of the simulation indicate the efficiency and availability of the methods.