基于数据的超宽带SAR的运动补偿方法
doi: 10.3724/SP.J.1146.2005.00654
Signal Based Motion Compensation for Ultra-wide Band SAR
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摘要: 基于超宽带SAR(UWB-SAR)回波数据估计多普勒调频率误差，为了准确提取和补偿该误差，本文提出了一种改进MapDrift(MD)自聚焦方法，消除了正侧闪烁和合成孔径长度太大造成的不利影响；通过插值拟合运动误差以及循环误差补偿弥补了子孔径数目有限、飞机速度估计过于离散的不足，实现了MD对二次以上高阶相位误差的补偿，使MD能够适用于复杂的飞行条件(如无人机)。实际UWB-SAR数据的补偿结果验证了该方法的有效性。Abstract: This paper presents a signal based Doppler rate estimation and compensation method to form a well focused Ultra-Wide Band Synthetic Aperture Radar (UWB-SAR) image. A refined MapDriftt(MD) autofocus technique is promoted to improve its original performance in UWB-SAR. In the refined MD, some implementation skills are adopted to accommodate the broadside sparking and the long aperture. Further more, the estimated Doppler rate error is interpolated and compensated in an iteration manner. As a result, higher order phase errors are compensated and this enable the refined MD technique to be capable in applications with large motion error, for example in UAV SAR. Finally the refined MD technique is verified by real UWB-SAR data imaging.
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