基于二维逆滤波的机载SAR 自聚焦算法

Autofocus Algorithm for Airborne SAR Based on the Two-Dimensional Inverse Filtering

摘要:

在聚束合成孔径雷达(SAR)自聚焦处理时,残留距离徙动(RRCM)必须在自聚焦处理之前完全去除,否则 将会严重降低自聚焦的性能。本文提出了一种基于二维逆滤波的自聚焦算法,该算法在补偿相位误差的同时也补 偿掉距离和方位的二维耦合相位,消除了RRCM对自聚焦的影响,提高了逆滤波自聚焦算法的性能。最后通过实 测数据处理验证了本文提出的二维逆滤波自聚焦算法的有效性。

Abstract:

For spotlight mode synthetic aperture radar (SAR) autofocusing, the traditional autofocus algorithm might sufferfrom performance degradation in the presence of residual range cell migration. In this paper, a two-dimensional inverse fil.tering autofocus algorithm was presented. The algorithm not only could compensate the azimuth phase error but also couldremove the coupling terms between range and azimuth frequency domain, which avoided the effect caused by the RRCM inautofocus processing and improved the performance of inverse filtering autofocus algorithm. The results processed by realmeasured data indicated the effectiveness of the proposed method.