机载高分辨滑动聚束SAR成像处理方法

The Method of Imaging For Air-borne Sliding Spotlight SAR

  • 摘要: 针对机载滑动聚束合成孔径雷达(SAR)高分辨率成像问题,在提出采用参考信号进行系统通道误差校正和高分辨滑动聚束成像运动补偿方法的基础上,结合基带方位向变标(BAS)算法,给出一种机载高分辨率滑动聚束SAR成像方法。首先,在频域推导了基于参考信号对回波信号进行幅度校正和相位补偿的方法;然后基于斜视成像几何模型,推导了机载滑动聚束SAR平台运动参数与多普勒参数之间的关系,给出从多普勒估计参数中估计运动参数和补偿运动误差的方法。采用该成像处理方法,某型星载SAR机载试飞试验成功实现了滑动聚束模式高分辨率成像,验证了方法的有效性。

     

    Abstract: Aiming at airborne sliding spotlight synthetic aperture radar (SAR) high-resolution imaging, a correction algorithm of system channel error using reference signal and a motion compensation method for airborne sliding spotlight mode is proposed. Integrated with the BAS algorithm, an innovative imaging procedure for airborne sliding spotlight SAR is presented. Firstly, the factor of amplitude correction and phase compensation by means of reference signal for echo data is derived from frequency-domain. Then, the motion compensation is studied based on squint geometry model, the relationship expression between Doppler parameters and platform motion parameters is deduced. After that, the motion error is estimated and compensated using the Doppler parameters estimated exactly from measured echo data. The successful high-resolution sliding spotlight imaging of airborne measured data for a certain space-borne SAR system validation shows the effectiveness of proposed method.

     

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