匀转速逆合成孔径雷达的越距离徙动补偿

Migration through Range Resolution Cell Correction Algorithm for Uniform Rotation Target ISAR Imaging

针对ISAR系统中的匀转速目标,本文提出了一种有效的校正由目标均转速旋转引起的越距离徙动(MTRC)的方法,对方位向上越距离徙动进行校正。它采用基于PD算法的Radon变换在方位向上得到精确的二次相位系数估计值,然后直接在时域上对越距离徙动校正,获得了更高的分辨率。Outlier-delete算法是一种在时域校正方位向越距离徙动的算法,在高信噪比条件下可以实现很好的聚焦效果,而在低信噪比条件下,该算法会出现严重误估计,导致聚焦失败。本文提出的Radon-PD算法具有很好的抗噪性,通过仿真并与Outlier-delete算法进行性能比较,验证了算法的有效性和可行性。

The paper presents an R-PD algorithm to correct the migration through resolution cells （MTRC） caused by the target＇s uniform rotation in ISAR imaging. Quadratic phase coefficient is estimated accurately with Radon transformation based on PD at the azimuth. Then, MTRC is corrected directly in time domain with higher resolution. Outlier-delete algorithm also corrects the MTRC in time domain to focus a clear image at high S/N; while it is invalid at low S/N. R-PD algorithm has good antinoise performance. The effectiveness of the method is verified with the simulation and comparison with Outlier-delete.