基线长度是影响测向精度的重要因素.长基线测向精度高,但基线长度大于半波长时会出现相位模糊.现有的相位解模糊算法大多限制了基线长度.本文在多基线比值法解模糊的基础上结合到达时间估计,提出了一种减小了基线长度限制条件的相位解模糊算法来实现长基线窄带信号测向.仿真结果表明,本算法解模糊概率不受基线长度影响,并且针对不同入射角的信号解模糊能力相同,在适当信噪比条件下能通过设置基线长度达到较高的测向精度.
Baseline length is a significant factor in direction finding.The longer the baseline is,the higher the accuracy is.When baseline length is more than half-wavelength,phase difference between two arrays will be ambiguity.Most existing unwrapping phase ambiguity algorithms limit baseline length.Combined with time of arrival(TOA) estimation,a kind of long baseline unwrapping phase ambiguity algorithm is presented to realize direction finding of narrowband signal,which reduces the restrictive conditions of baseline length.The simulation results show that the probability of unwrapping phase ambiguity is insensitive to baseline length and incident angle.High accuracy can be achieved in direction finding by setting baseline length under the appropriate signal to noise ratio(SNR).