一种新的ISAR距离对齐算法

距离对齐是逆合成孔径雷达(ISAR)成像处理中的或对齐精度不够高,或运算效率过低,无法满足ISAR实时成像的要求.由于距离对齐算法本质上是一种优化方法,基于优化原理,将启发式方法与搜索法相结合,提出了一种新的距离对齐算法.该算法结合使用频域法和累积互相关法,具体分两步实现:首先利用频域法进行粗对齐,然后将第一步得到的结果作为启发式信息进行累积互相关,大大减小了其搜索范围,得到了精确的距离对齐效果.通过将新算法与其他算法的运算量进行分析比较,结果表明该算法运算效率较高.而对实测数据的成像处理结果证明该算法具有良好的对齐精度.这说明新算法在效率和性能上达到了良好的平衡,适合于ISAR实时成像.

A novel range alignment algorithm for ISAR

Range alignment is a key step in ISAR imaging.Due to their low accuracy or low efficiency,the conventional range alignment algorithms can't satisfy the requirements of real-time ISAR imaging.Since range alignment algorithm is essentially an optimization method,a novel range alignment algorithm is proposed in this paper based on the principles of optimization.It is a combination of both heuristic method and searching method,which is implemented in two steps.In the first step,a coarse result is obtained via frequency domain algorithm.The coarse result is then used as heuristic information of the accumulated maximum cross correlation operation in the second step,to sharply reduce the searching space.After these two steps,an accurate result could be achieved.The analysis of the computational complexities of this algorithm and other algorithms proves that this novel algorithm holds a high efficiency.The imaging tests with real ISAR data demonstrate that it also maintains a high accuracy.So the novel algorithm achieves a good balance between the efficiency and the accuracy.It is suitable for real time ISAR imaging.