利用高分辨率 DEM 数据提高雷达测雨精度的方法

摘要

With the data of high-resolution digital elevation model(DEM) and the height value at 0 ℃layer ,under the assuming condition of standard atmospheric refractive and in the consideration of the surrounding barrier layer and the bright band at 0 ℃,the distribution of elevation angle of seven radars and the detection range of quantitative precipitation in Hunan was calculated according to the radar volume scan mode VCP21 commonly used.The results showed that the radius of radar detection in Changsha,Changde,Yueyang,Huaihua,Shaoyang,Chenzhou, Yongzhou and Zhengzhou was177 .00,179.00,188.40,124.85,162.06,145.50and 144 .17 km,and the maximum detection range was in Yu-eyang and the minimum,Huaihua.In flooding season,the estimation of quantitative precipitation detection,which was from the radar network in Hunan province,could be basically used for the rain-monitoring in whole province based on the removal of the influence of the bright band at 0℃. The accuracy of quantitative precipitation estimation would be improved.%利用高分辨率的数字高程模型（DEM）数据和0℃层高度值，在假定标准大气折射条件下，综合考虑周边地物的阻挡和0℃层亮带因素，根据目前雷达常使用体扫模式 VCP21，计算了湖南省7部雷达的波束阻挡仰角分布及雷达定量估测降水产品的探测范围。结果表明，对于湖南的4月份，长沙、常德、岳阳、怀化、邵阳、永州和郴州雷达的探测半径分别是177．00、179．00、188．40、124．85、162．06、145．50、144．17 km，岳阳雷达的探测范围最大，而怀化雷达的探测范围最小；对汛期而言，应用湖南省建设的雷达网，获取的定量估测降水业务的探测范围在消除0℃层亮带影响的同时基本能实现对全省区域的降水监测，有利于提高定量估测降水的精度。