基于恒加速度模型的斜视SAR成像CA-ECS算法

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

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(Con-stantAcceleration 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.

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 compensationfactors 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.