提出一种基于弹载双均匀圆阵(uniform circular array, UCA)的相干信源二维波达方向(direction of arrival, DOA)估计算法。算法首先沿轴向对阵列进行虚拟平移,利用空间平滑技术处理数据以恢复协方差矩阵的秩,实现相干信号解相干,再依据轴向双圆阵列的结构特点构造波达方向矩阵,对波达方向矩阵进行特征值分解可得到包含俯仰角信息的特征值和包含俯仰角信息与方位角信息的特征矢量,完成相干信源DOA估计。算法将波达方向矩阵法引入均匀圆阵,估计参数自动配对,同时避免了常规算法的二维谱峰搜索,实时性好。仿真结果表明,与矩阵重构的均匀圆阵旋转不变子空间(uniform circular arrayestimation of signal parameters via rotational invariance techniques, UCA-ESPRIT)算法相比,本文算法计算量较小,分辨率高。
Based on missileborne dual uniform circular arrays (UCA), an estimation algorithm about two-dimensional direction-of-arrival (DOA) of coherent signals is proposed. Firstly, the algorithm utilizes spatial smoothing techniques to regain the rank of covariance matrix by processing the data gathered by virtually arrays moving along the axial direction. Then, according to the structure of the dual UCA, a DOA matrix is constructed. Eigenvalues and eigenvectors can be acquired by performing eigenvalue decomposition of the DOA matrix. According to the eigenvalues and eigenvectors with elevation and azimuth information, the DOA of coherent signals can be estimated. The proposed algorithm utilizes the DOA matrix method to solve the parameter estimation in the UCA fields. Thus the algorithm requires no parameter alignment and 2D spectrum peak searching. The simulation results indicate that the algorithm has low computational complexity and high resolution characteristics compared with UCA-ESPRIT algorithm.