基于ERA-Interim的L波段探空秒级风速算法检验

Evaluation of a L-Band Wind Speed Calculation Algorithm Based on ERA-Interim

本文基于L波段探空雷达高垂直分辨率方位数据,通过在不同探空高度处选取不同尺度的时间窗口,设计了计算秒级风速的3种方案。通过比较3种计算方案得到的秒级风速与ERA-Interim再分析资料在平均偏差Bias和均方根误差RMSE等指标上的差异,给出了计算秒级风速的最优算法。结果表明:由于雷达的定位存在系统偏差,窗口选取过大或过小均会引入较大的秒级风速误差,选取适当尺度的时间窗口是准确计算秒级风速的必要条件。另外,基于ERA-Interim再分析资料具备良好的时空一致性,本文提出了1种检验L波段秒级风速算法优劣的新方案。

Based on the high vertical-resolution position data of L-band and radiosondes,three schemes for calculating second-level wind speed are designed by selecting different time windows at different sounding heights.The calculated second-level wind speed and ERA-Interim reanalysis data are compared on different indexes：the amount of data,the average deviation（Bias）,and the root mean square error（RMSE）,which indicate the optimal algorithm to calculate the second wind speed.The results show that the appropriate length of time window is necessary to accurately calculate the second wind speed.Given the radar positioning system deviation,the second wind speed error will be larger if the time window is chosen too large or too small.Based on the ERA-Interim reanalysis data with good spatial and temporal consistency,this paper presents a new scheme to evaluate the L-band second-level wind speed calculation.