Adaptive Beamforming Using Steering Vector Correction for Phased-Array Weather Radar
Adaptive Beamforming Using Steering Vector Correction for Phased-Array Weather Radar
复制标题
使用相控阵气象雷达转向矢量校正的自适应波束形成
DOI：
10.1109/jstars.2021.3106002
复制
发表时间：
2021
影响因子：
5.5
通讯作者：
and Y. Hobara
中科院分区：
文献类型：
--
作者：
H. Kikuchi;E. Yoshikawa;T. Ushio;and Y. Hobara
2017年12月，部署了双偏振（DP）相控阵天气雷达（PAWR）来观测日本东京的降水情况。 DP-PAWR具有以下特点：在60公里范围内进行30秒体积扫描的高时间分辨率观测、15公里高度以下的高密度观测、使用双偏振观测改进的降雨率估计以及比重计分类能力。为了实现高时间分辨率观测，波束宽度高达 5° 的宽发射波用于仰角。尽管傅立叶域数字波束成形可用于接收波，但由于地面杂波回波，使用这种类型波束成形的天线方向图的高旁瓣电平会导致大量误差（例如，高估接收功率）。针对这一问题，针对单偏振相控阵雷达，提出了一种基于最小均方误差（MMSE）的自适应波束形成方法。在本研究中，开发了信号处理程序，包括实际测量数据的转向矢量校正，以将 MMSE 方法应用于 DP-PAWR。通过数值模拟评估相位误差和地面杂波对双偏振参数的影响。随后，将所提出的方法应用于 DP-PAWR 的实际测量数据。结果发现，使用所提出的方法实现的杂波抑制明显优于使用傅里叶域数字波束形成实现的杂波抑制。
In December 2017, a dual-polarized (DP) phased-array weather radar (PAWR) was deployed to observe precipitation in Tokyo, Japan. The DP-PAWR has the following characteristics: high-temporal-resolution observations for a volume scan of 30 s in a 60 km range, high-density observations below a 15 km altitude, improved rain rate estimation using dual-polarimetric observations, and hydrometer classification abilities. To achieve high-temporal-resolution observations, wide transmitted waves with a beam width up to 5° are used for elevation angles. Although Fourier-domain digital beamforming can be used for receiving waves, the high sidelobe level of the antenna pattern using this type of beamforming results in substantial errors (e.g., overestimation of received power) because of ground clutter echoes. To solve this problem, an adaptive beamforming method based on the minimum mean square error (MMSE) was developed for a single-polarization phased-array radar. In this study, signal processing procedures, including the steering vector correction of real measurement data, are developed to apply the MMSE method to the DP-PAWR. The effect of phase errors and ground clutter on the dual-polarimetric parameters is evaluated via numerical simulations. Subsequently, the proposed method is applied to real measurement data of the DP-PAWR. Consequently, it is found that the clutter suppression achieved using the proposed method is clearly superior to that achieved using Fourier-domain digital beamforming.