The accuracy of rainfall estimates by radar as a function of range
The accuracy of rainfall estimates by radar as a function of range
复制标题
雷达降雨量估算的准确性与距离的关系
DOI：
--
复制
发表时间：
1992
期刊：
影响因子：
--
通讯作者：
D. Tees
中科院分区：
文献类型：
--
作者：
F. Fabry;G. Austin;D. Tees
使用分辨率为200米的体积扫描天气雷达收集了附近对流风暴的高空间分辨率数据，使用高分辨率（20米）垂直指向雷达收集了层状事件的高空间分辨率数据。利用这些高分辨率图像模拟了由于雷达波束交叉或过冲特征（如亮带）而造成的扫描雷达估计降雨量的误差。人们发现，这些影响确定了雷达的最大有用范围，这是主要气象条件（例如亮带高度、强小区直径和高度）的强函数。
短时间内亮带高度的突然变化和在其厚度上观察到的大散射限制了反射率垂直廓线的校正在层状雨事件中可以预先计算的准确性。提出了一种利用垂直指向雷达来真实的实时产生这些修正的方案。对流事件显示了足够显著的风暴间变化，因此需要谨慎地将雷达的有用范围扩展得太远。
High-spatial-resolution data were collected for nearby convective storms by using a volume scanning weather radar with 200m resolution, and for stratiform events by using a high-resolution (20m) vertically pointing radar. Errors in the estimation of rainfall by the scanning radar, due to the radar beam intersecting or overshooting features such as the bright band, were simulated by using these high-resolution images. It was found that these effects define a maximum useful range for the radar that is a strong function of the prevailing meteorological conditions (e.g. bright-band height, intense cell diameter and height).
Sudden changes in bright-band height over short times and the large scatter observed in its thickness limit the accuracy with which corrections for the vertical profile of reflectivity may be precalculated in stratiform rain events. A scheme for using a vertically pointing radar to produce these corrections in real time is proposed. the convective events show enough significant storm-to-storm variability that caution is required in extending the useful range of the radar too far.