SAR系统收发通道幅相误差实时校正

分辨率是衡量合成孔径雷达系统性能的重要指标,由于系统收发通道带内幅相误差的存在会造成回波信号失真,相应的脉冲压缩效果也随之恶化,继而影响SAR成像的距离向分辨率。为对其进行实时校正,提出用相关加窗法提取误差,并用复切比雪夫逼近法设计复系数FIR滤波器的方案。结果显示,校正后的脉冲压缩效果得到改善,且校正效果与FIR阶数有关。最后得出校正后的峰值旁瓣比和积分旁瓣比会随着滤波器阶数增加而降低,并趋于稳定的结论。

Real-time Correction of Channel Amplitude and Phase Error in SAR System

The resolution of synthetic aperture radar is an important index to measure the performance of the system. Because of the amplitude and phase error in the transmitting and receiving channel of the system, the echo signal is distorted, and the corresponding pulse compression effect deteriorates, which affects the range resolution of SAR imaging. In order to correct the amplitude and phase error in real time, the correlation windowing method is used to extract the error, and a complex FIR filter is designed by complex Chebyshev approximation method. The results show that the corrected pulse compression effect is improved, and the corrected effect is related to the order of the filter. Finally, it is concluded that the PSLR and ISLR of the corrected pulse compression decrease with the increase of filter order, and gradually become stable.