Weather Observation by an Electronically Scanned Dual-Polarization Phase-Tilt Radar
Weather Observation by an Electronically Scanned Dual-Polarization Phase-Tilt Radar
复制标题
电子扫描双偏振相倾雷达天气观测
DOI：
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发表时间：
2018
影响因子：
8.2
通讯作者：
S. Frasier
中科院分区：
文献类型：
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作者：
K. Orzel;S. Frasier
本文介绍了X波段双极化固体一维电子扫描“相位倾斜”天气雷达（PTWR）及其扫描结构。在该架构中，当扫描离开波束时，真实仰角从标称阵列倾斜角减小，并且真实方位角从请求方位角增大。此外，这种扫描几何形状引起倾斜角效应，这在较高高度倾斜时尤其显著。在选定的极化变量，由于这种影响的潜在偏见的预测。对于10°以下的仰角，其中极化测量是最有价值的，预测偏差是可以忽略的。PTWR于2014年春季部署在美国德克萨斯州的阿灵顿，为期八周，收集了大量天气事件的数据。采用双极化抛物面天线的机械扫描磁控管雷达的直接接近（250 m远）允许进行定性和定量数据比较。我们发现两个雷达系统的观测结果的差异并不归因于上述偏差，而主要是由于两个雷达的采样量的差异。我们还发现，在高海拔倾斜，耦合的真实仰角与阵列相对方位扫描角复杂的解释功能在一个恒定的高度，如熔化层。
A dual-polarized X-band solid-state 1-D electronic scanning “phase-tilt” weather radar (PTWR) and its scanning geometry are presented. In this architecture, the true elevation angle decreases from the nominal array tilt angle and the true azimuth angle increases from the requested azimuth as one scans off boresight. Additionally, this scanning geometry induces a canting angle effect, which can be significant especially at higher elevation tilts. The predictions of potential biases in selected polarimetric variables due to this effect are derived. For elevation angles below 10°, where polarimetric measurements are of most value, predicted biases are negligible. The PTWR was deployed in Arlington, TX, USA, for an eight-week period during Spring 2014 collecting data on a number of weather events. The direct proximity (250 m away) of a mechanically scanning magnetron-based radar, employing a dual-polarized parabolic antenna allowed for a qualitative and quantitative data comparison. We find the differences in the observations made by the two radar systems are not attributable to the aforementioned biases, but appear primarily due to differences in sampling volumes of the two radars. We also find that at high-elevation tilts, the coupling of the true elevation angle with the array-relative azimuth scan angle complicates the interpretation of features at a constant altitude such as the melting layer.