时频分析在线性调频信号相位误差估计中的应用

合成孔径雷达(SAR)使用线性调频(LFM)信号作为发射脉冲，带有相位误差的畸变线性调频信号会严重影响到雷达成像的效果．本文分析了二次相位误差对脉冲压缩信号的影响，并采用时频分析的方法对畸变回波信号进行处理．首先利用短时傅立叶变换得到信号的时频分布，再经过傅立叶插值和最小二乘拟合的方法估计出信号的调频斜率．最后用估计值对畸变信号进行相位补偿，得到了令人满意的仿真结果．

Application of Time-Frequency Analysis in Phase Error Estimate of LFM Signal

Theoretically, Linear Frequency Modulated(LFM) signal should be transmitted in Synthetic Aperture Radar(SAR) system. While in practical SAR system, the return signal may be involved with phase error which affects the resolution of SAR. In this paper, firstly, we analyze the effect of quadratic phase error on SAR signal pulse compression. Secondly we put forward a method to estimate the quadratic phase error. And finally simulation experiments show the high accuracy in estimating the quadratic phase error by means of the presented method.