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提出了一种相干宽带线性调频(LFM)信号的波达方向(DOA)估计新方法.该方法利用LFM信号在分数阶Fourier域上的解线调特性,构造出新的解线调域阵列数据模型,然后结合传统的矩阵重构解相干以及MUSIC算法实现相干LFM信号的DOA估计.若同时存在多组相干LFM信号入射,则首先在不同的能量聚集域上将各信号组分离,然后逐一进行各组内相干信号的DOA估计.该方法充分地挖掘了观测信号所包含的时频信息,增加了可检测的DOA数目,提高了分辨性能和抗噪声性能.此外,该方法无冗余阵元与孔径损失,且适用于任意流型阵列.仿真结果显示,在DOA估计的均方根误差(RMSE)相同时,与传统方法相比,本方法可获得8dB左右的信噪比增益.“,”A novel direction of arrival(DOA) estimation method for coherent wideband linear frequency modulation(LFM) signals was proposed.Based on the dechirping property of LFM signal in fractional Fourier domain,a new array data model was constructed,then the matrix reconstruction and MUSIC algorithm were used to estimate the DOA of co-herent LFM signals.If there were multiple groups of coherent LFM signals incident,separated them in different en-ergy-concentrated domains first,then carried the DOA estimation on each of the groups.Owing to fully excavating the time-frequency information included in observed signals,this method has good resolution ability and anti-noise perform-ance,and the number of DOA that can be resolved is also increased.In addition,this method has no array redundancy and aperture loss,and can be applied to arbitrary array manifold.Simulation results show that this method can obtain nearly 8dB signal-to-noise ratio gain compared with the conventional method.