基于 Keystone 变换的俯冲加速运动 SAR 成像算法

摘要

俯冲加速条件下的SAR成像算法是当前SAR成像领域中一个热门研究课题。受到加速度的影响，其距离方程不再是单纯的双曲线形式，从而导致无法根据驻定相位原理求得俯冲加速SAR回波的二维频谱解析表达式。因此，传统SAR频域成像算法不再适用于俯冲加速SAR成像。论文从SAR距离徙动特性着手，利用Keystone变换实现对俯冲加速SAR的线性徙动校正，从而实现距离向和方位向的二维解耦合，得到最终的SAR聚焦图像。%SAR image formation algorithm under diving and accelerated is a hot research subject in SAR field .Due to the range equation with a more complex form ,it is difficult to solve an analytical two‐dimensional frequency spectrum using principle of stationary phase .Thus ,the traditional algorithms are invalid for imaging in dive and accelerated motion .This paper proposes an efficient image formation algorithm ,using keystone transform to correct the linear range cell migration . Finally ,the focused SAR image can be obtained via two‐dimensional fourier transform .