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| Motion Compensation for Airborne SAR with Synthetic Bandwidth |
| Zhang Mei①② Liu Chang① Wang Yan-fei① |
①(Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, China)
②(Graduate University of Chinese Academy of Sciences, Beijing, 100039, China) |
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Abstract Bandwidth synthetic technique provides a fine range resolution for the advanced airborne SAR system. In strip-map mode, in order to get an as good azimuth resolution as the range, the precise motion compensation is important. This paper studies several key issues of the “two-step” motion compensation method in the bandwidth synthetic system. In the first compensation step the precise Inertial Measurement Unit (IMU)/GPS data is used, the real target distance and the ideal airborne line are always unknown. In this paper, the corner reflectors are used to estimate these values. And in the second step, an improved Phase Gradient Autofocus (PGA) algorithm is used to compensate the residual time-mutative phase error. Real data testifies that after the “two-step” compensation the azimuth resolution better than 0.25 m is obtained finally.
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Received: 10 March 2011
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Corresponding Authors:
Zhang Mei
E-mail: zhangmei2011@gmail.com
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2011, Vol. 33 
