高性能空时二维角度估计改进算法

干扰角度估计是数字阵列雷达抗干扰的基础，本文针对实际数字阵列天线阵元间距大于半波长导致大角度估计时阵元相位出现模糊问题，提出一种新的基于时空DOA矩阵的多目标高性能二维角度估计算法。该算法首先计算时空DOA矩阵并进行特征值分解，接着利用空时矩阵特征向量与来波导向矢量匹配特性，对估计得到的各导向矢量分别进行相位解模糊，进而利用导向矢量联立方程组，得到各来波角度信息的最小二乘解。相位解模糊过程主要通过计算多组模糊解对应的导向矢量与实际估计得到的导向矢量的相关性，选取相关值最大的一组模糊解作为真实解来实现。仿真与数字阵列天线实测结果表明，与时空DOA矩阵法相比，本文算法具有更高的测角精度和更加稳健的输出性能。 

Improved algorithm for high performance space-time 2-dimensional angle estimation

Jamming angle estimation is the fundamental issue of digital array radar for anti-jamming improvement. A new two-dimensional high-performance angle estimation algorithm based on space-time DOA matrix is proposed in this paper under the circumstance that the element spacing of digital array antenna is larger than half wavelength, which leads to phase ambiguity for large jamming angle. Firstly, the space-time DOA matrix is calculated and the eigenvalue decomposition is carried out. Then, the phase unwrapping of each estimated steering vector is performed respectively, which fully uses the matching characteristic between space-time matrix eigenvector and the wave-oriented vector. Finally, the least square solutions of each wave angle are obtained using a series of equations from the estimated steering vector. The phase ambiguity problem is solved by calculating the correlation between the steering vectors corresponding to the set of fuzzy solutions and the steering vectors obtained from estimation, and then choosing the maximum correlation value as the true solution. The simulation and experimental results of digital array antenna demonstrate that the proposed algorithm present higher angle measurement accuracy and more robust performance than those of the space-time DOA matrix method.