北京气象局天气雷达回波阻挡订正技术研究

Study on Weather Radar Echo Block Correction Technology of Beijing Meteorological Bureau

经过多年的建设,我国已经形成了相当规模的天气雷达监测网。由于我国地形起伏和高大建筑物的影响,新一代天气雷达在正常使用的过程中不可避免地会遇到地形遮挡的问题。以北京南郊雷达站为例,利用3 s高分辨率地形数据,充分考虑地球曲率和标准大气折射的影响下,模拟了雷达波束遮挡。根据天气雷达估测降水系统中关于地形遮挡补偿的算法对地形遮挡部分进行补偿,同时对于新增加的建筑物遮挡,增加了人工编辑地形遮挡率。最后利用天津雷达站(未遮挡部分)和北京雷达站(遮挡部分)重合的部分来验证地形遮挡补偿的有效性;此方法显著提高了混合扫描反射率产品(HSR)及降水类一系列衍生产品的质量。

After years of efforts,China has already built a considerable scale of radar monitoring network. It is not avoidable to solve the terrain blockage problems when the new generation weather radar is used,because China is a vast country and the landform is very complicated. Taking Beijing South suburb radar station as an example,the beam blockage by using the 3-second high resolution terrain data under the full considerations of the influence of earth curvature and atmospheric refraction was simulated. Simulated beam blockage results were verified by contrasting with the PPI product of radar observation. The results show that： the simulated beam blockage agreements with radar observation well. Compensating the terrain shade part according to the terrain block compensation algorithm in the weather radar system of estimating precipitation. At the same time,for the new building block,increasing manual editing terrain shade rate. Finally,the overlapping part of Beijing radar station（ part of terrain blockage） and Tianjin radar station（ no terrain blockage） to verify the validity of the terrain shade compensation were used. This way observably improves the quality of the products including the mix scanning reflectivity products（ HSR） and a series of precipitation derivatives.