随机相位噪声对成像的影响及其改善方法

从雷达成像的原理出发,分析了方位向随机相位误差对点目标成像的影响,提出了通过对线性调频信号模糊图进行旋转,矩阵奇异值分解来减弱随机相位噪声影响的方法。仿真结果表明,该方法能有效地减弱随机相位对成像噪声的影响。

Influence of Random Phase Noise on SAR Imaging and Its Improvement

Random phase error in the radar data will badly influence the pulse compress effect and blur theimage, due to the difficulty of removing this multiplicative phase noise. Document〔5,6〕threat the noise bycomputation of the high order statistics of received. However, this method requires large number ofsampling data to satisfy the stability of the statistics, which limits the application of this method.Document〔7〕brought out a new way to enhance Chirp signal from strong additive background randomnoise by rotating the short time Fourier transform of the signal, singular value decomposition and lineapproximation.This paper analyzes the influence of random phase noise from azimuth on SAR imaging first. Then onthe base of document〔7〕, a novel and effective way of rotation of Ambiguity Function and singular valuedecomposition to take place of matched filter is put forward, which is applicable to moving targetsdetecting and imaging since it is always presumed several strong reflecting point from the moving target.Simulation results are presented to confirm the theoretical results, showing that the method in this paper ismore effective than filters in time or frequency domain. However, a shortcoming is that the number ofecho signals will affect the filtering result by this method.