An Estimator for Weather Radar Doppler Power Spectrum via Minimum Mean Square Error
An Estimator for Weather Radar Doppler Power Spectrum via Minimum Mean Square Error
复制标题
基于最小均方误差的天气雷达多普勒功率谱估计器
DOI：
10.1109/tgrs.2020.3044111
复制
发表时间：
2021
影响因子：
8.2
通讯作者：
Ushio Tomoo
中科院分区：
文献类型：
--
作者：
Yoshikawa Eiichi;Takizawa Naoya;Kikuchi Hiroshi;Mega Tomoaki;Ushio Tomoo
提出了一种基于最小均方误差（MMSE）的天气雷达多普勒功率谱（DPS）估计方法。为了探测大多发生在大气层最低几公里内的恶劣天气现象，气象雷达必须将其波束指向低仰角，并且从这种观测中接收到的信号通常包含来自地面和建筑物的反射，即所谓的地面杂波。MMSE估计器，这是一个自适应谱估计器，允许天气雷达DPS获得良好的减少地面杂波污染。通过数值模拟，假设不同的降水和地杂波场景和DPS估计参数值的MMSE估计器进行了检查。MMSE估计器提供的DPS几乎一样准确，从传统的傅立叶和加窗傅立叶估计器在模拟没有地面杂波和更好的DPS比这些估计器在地面杂波的存在。最小均方误差估计器比Capon估计器对地杂波污染有更好的抑制作用。作为统计评估的结果，具有70 dB的强杂波噪声比的地杂波信号仅出现在MMSE DPS的窄速度范围内，从-2到2 m/s，并且在该速度范围之外仅导致1 dB的平均误差和标准误差的退化。最小均方误差估计器也被应用到实际天气雷达接收的信号中，并且演示了具有类似低地杂波污染的降水信号的DPS估计。
This article proposes a method for estimating the Doppler power spectrum (DPS) of a weather radar via minimum mean square error (MMSE). In order to detect severe weather phenomena that mostly occur within the lowest few kilometers of the atmosphere, weather radars have to direct their beams at low elevation angles, and the received signals from such observations usually contain reflections from the ground and buildings, so-called ground clutter. The MMSE estimator, which is an adaptive spectral estimator, allows weather radar DPSs to be obtained with excellently reduced ground clutter contaminations. The MMSE estimator was examined by numerical simulations, which supposed various precipitation and ground clutter scenarios and DPS estimation parameter values. The MMSE estimator provided DPSs almost as accurate as those from the traditional Fourier and windowed Fourier estimators in simulations with no ground clutter and much better DPSs than those estimators in the presence of ground clutter. Furthermore, the MMSE estimator gave better suppression of ground clutter contamination than the Capon estimator, which is another adaptive spectral estimator. As a result of statistical evaluations, ground clutter signals with a strong clutter-to-noise ratio of 70 dB appeared only in a narrow velocity range of the MMSE DPS, from −2 to 2 m/s, and caused degradation of the mean and standard errors outside this velocity range by just 1 dB. The MMSE estimator was also applied to signals received by actual weather radar, and DPS estimation of precipitation signals with similarly low ground clutter contamination was demonstrated.