基于恒加速度模型的斜视SAR成像CA-ECS算法

针对空载SAR俯冲模式下的高精度运动补偿方法进行研究,推导了恒加速度运动条件下的等效斜视距离模型,基于该模型推导出Extend Chirp Scaling相位补偿因子的数学表达式,提出了一种CA-ECS(Constant Acceleration ECS)算法.该算法的相位补偿因子包含多个方向速度和加速度参数,能够实现恒加速度条件下的运动补偿,是一种通用性强、适用面广的子孔径成像算法.计算机仿真结果表明本文使用的等效斜视距离模型的误差较小,CA-ECS算法能有效地完成加速度运动补偿.

CA-ECS Algorithm for Squinted SAR Imaging Based on Constant Acceleration Model

This paper concentrates on accurate motion compensation method for airborne SAR in diving model.The equivalent squint range model is deduced in the case of constant acceleration movement and CA-ECS(Constant Acceleration-Extended Chirp Scaling) imaging algorithm is proposed with new phase compensation factors based on this range model.The influences of multi-directional velocities and accelerations are taken into account in phase(compensation)factors of CA-ECS algorithm,so motion compensation with acceleration can be achieved via phase (compensation).This algorithm is a more versatile and applicable imaging algorithm for subaperture data.The computer simulation results illustrate that the squint range model has less error and CA-ECS algorithm can be used to accomplish motion compensation with acceleration efficiently.