一种基于混沌调频信号的稀疏雷达成像

A Sparse Radar Imaging Method Based on Chaotic Frequency-Modulated Signal

稀疏雷达成像是指将稀疏信号处理理论引入雷达成像并有机结合而成的微波成像新方法。混沌调频信号是一种基于混沌映射产生的类噪声信号,与采用线性调频信号的雷达相比,它的波形之间互不相干且具有随机性,提升了雷达的隐蔽性能;其模糊函数形状为图钉形,增强了稀疏雷达成像中观测矩阵的列不相关性。利用支持分布式运算的交替方向法对稀疏场景进行重构,仿真实验表明,基于混沌调频信号的稀疏雷达成像可以在降低信号采样率的条件下对原始场景进行准确重建。

The sparse radar imaging is a new microwave imaging method which combines the sparse signal processing theory with the radar imaging.Chaotic frequency-modulated（FM）signal is a kind of noiselike signal based on chaotic mapping.Compared with the chirp signal,the waveforms of chaotic FM signal are irrelevant and random.This feature enhances radar＇s concealment performance.The thumbtack ambiguity function enhances the column irrelevance of the observation matrix in sparse radar imaging.The sparse scene is reconstructed by using the alternating direction method of multipliers（ADMM）,which supports distributed operations.The simulation results show that the chaotic FM signal based sparse radar imaging method can reconstruct the scene accurately under a lower sampling rate.