School of Electronic Science and Engineering (National Exemplary School of Microelectronics), University of Electronic Science and Technology of China, Shahe Campus, Section 2, North Jianshe Road, Chengdu 610054, China.
Sensors (Basel). 2018 May 12;18(5):1534. doi: 10.3390/s18051534.
Direction of Arrival (DOA) estimation of low-altitude targets is difficult due to the multipath coherent interference from the ground reflection image of the targets, especially for very high frequency (VHF) radars, which have antennae that are severely restricted in terms of aperture and height. The polarization smoothing generalized multiple signal classification (MUSIC) algorithm, which combines polarization smoothing and generalized MUSIC algorithm for polarization sensitive arrays (PSAs), was proposed to solve this problem in this paper. Firstly, the polarization smoothing pre-processing was exploited to eliminate the coherence between the direct and the specular signals. Secondly, we constructed the generalized MUSIC algorithm for low angle estimation. Finally, based on the geometry information of the symmetry multipath model, the proposed algorithm was introduced to convert the two-dimensional searching into one-dimensional searching, thus reducing the computational burden. Numerical results were provided to verify the effectiveness of the proposed method, showing that the proposed algorithm has significantly improved angle estimation performance in the low-angle area compared with the available methods, especially when the grazing angle is near zero.
由于目标地面反射图像的多径相干干扰，低空目标的到达方向（DOA）估计较为困难，尤其是甚高频（VHF）雷达，其天线在孔径和高度方面受到严重限制。本文提出了一种将极化平滑和广义 MUSIC 算法相结合的极化敏感阵列（PSA）极化平滑广义多重信号分类（MUSIC）算法，以解决这一问题。首先，利用极化平滑预处理来消除直达信号和镜面信号之间的相干性。其次，我们构建了用于低角度估计的广义 MUSIC 算法。最后，基于对称多径模型的几何信息，引入了所提出的算法将二维搜索转换为一维搜索，从而降低了计算负担。数值结果验证了所提出方法的有效性，结果表明，与现有方法相比，该算法在低角度区域的角度估计性能有显著提高，特别是当掠射角接近零时。
