导弹在俯冲下降运动中飞行姿态变化较大、造成目标斜距表达式较为复杂,给弹载合成孔径雷达(SAR)成像算法提出了新的要求。针对这个问题,该文提出了一种新的弹载SAR成像方法,首先将目标斜距方程近似为慢时间的4阶近似式,再利用卡尔丹方程解得驻相点的精确解,进而得到信号的2维频谱表达式,然后以此为基础推导了相应的成像算法。最后,点目标仿真结果说明,与传统方法相比该文所提方法具有良好的成像效果,能够在导弹俯冲下降运动中实现全孔径高分辨成像。
Due to the variational flight path during the diving maneuver,the range function of the point target for the missile-borne SAR becomes complicated.Thus,a new imaging method is proposed in this paper.Firstly,the target range function is expanded to a quartic polynomial.Secondly,the stationary point is solved via the Cardano's formula,and then the tow-dimensional spectrum is obtained,based on which a new imaging algorithm is derived.Finally,the simulation result of the point targets shows that the algorithm proposed is effective to give a high resolution imagery with the entire aperture of the missile-borne SAR than the traditional method.