对直达波和杂波条件下的阴影逆合成孔径雷达(SISAR)目标成像问题进行了研究。分析了直达波和杂波对侧影像畸变和运动补偿的影响,提出了一种新的直达波和杂波干扰下目标SISAR成像方法,即将回波信号与参考信号进行模拟对消,并利用目标回波的频谱特性剔除残留直达波,再对目标运动参数进行粗估计,采用粗搜索和精搜索2步实施准确的运动补偿,最终获得失真度较小的目标侧影像。仿真实验验证了算法的有效性。
The imaging technology of shadow inverse synthetic aperture radar (SISAR) with direct wave and clutter jamming is researched. The adverse effects on shadow image precisions and motion compensation induced by direct wave and clutters are discussed to present a novel algorithm for SISAR. Firstly, target's echoes are cancelled with the analog reference signals. Then, the residual direct waves are eliminated according to the spectrum characteristics of the echoes. After the motion parameters of target are estimated roughly, the accurate motion compensation is carried out by using rough searches and fine searches. Finally, the final shadow image of target is obtained. Simulations validate the effectiveness of the algorithm.