快速扫描机载气象雷达多普勒解模糊算法

Doppler Ambiguity Resolution Algorithms for Airborne Weather Radar in Fast Scanning Mode

本文针对机载气象雷达前视快速扫描下的多普勒模糊问题,提出了两种多普勒解模糊算法:基于改进方位向波束形成算法和基于阻塞矩阵算法。基于改进方位向波束形成算法在传统的Capon波束形成的基础上,利用空间谱积分的方法对非期望信号协方差矩阵进行重构和对导向矢量进行估计,进一步提高了算法的鲁棒性,降低方位角估计误差;基于阻塞矩阵算法需要估计导向矢量,并利用导向矢量计算阻塞矩阵,将接收信号进行多普勒模糊相消预处理,阻塞每个多普勒频点的模糊多普勒分量,以达到解模糊的目的。通过仿真实验证明,两种方法均可以有效地恢复信号的多普勒信息,其中基于阻塞矩阵算法与基于改进方位向波束形成算法相比,有更优良的性能,并有更小的运算量。

Aiming at the Doppler ambiguity in airborne weather radar working in forward-looking and fast scanning mode,this paper proposes two Doppler ambiguity resolution algorithms which are based on improved azimuth beamforming algorithm and blocking matrix algorithm respectively.For the algorithm based on the improved azimuth beamforming,on the basis of the traditional Capon beamforming,the spatial spectrum integral method is used to reconstruct the covariance matrix of the undesired signal and estimate steering vector,which further improves the robustness and prevents the error from azimuth estimation.For the algorithm based on blocking matrix,steering vector needs to be estimated and the blocking moment is calculated by steering vector.Received signal is preprocessed by Doppler ambiguity cancellation to block ambiguous Doppler component of each Doppler frequency point,so as to achieve the purpose of ambiguity resolution.Simulation results show that the two algorithms can effectively recover the Doppler information of the signal.Compared with the algorithm based on improved azimuth beamforming,the algorithm based on blocking matrix has better performance and less computation.