基于多普勒天气雷达的低空多普勒速度的切变识别算法研究  

RESEARCH ON SHEAR DETECTION ALGORITHM BASED ON DOPPLER WEATHER RADAR FOR LOW-ELEVATION DOPPLER VELOCITY

作　　者：闫文辉[1] 黄兴友[1] 李盈盈 杨敏[1] 刘燕斐 YAN Wen-hui;HUANG Xing-you;LI Ying-ying;YANG Min;LIU Yan-fei(Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing Universityof Information Science & Technology, Nanjing 210044, China)

机构地区：[1]南京信息工程大学气象灾害预报预警与评估协同创新中心,江苏南京210044

出　　处：《热带气象学报》2019年第2期253-261,共9页Journal of Tropical Meteorology

基　　金：国家自然科学基金项目(41475034);国家重点基础研究发展计划(973计划)项目(2013CB430101)共同资助

摘　　要：低空风切变是影响航空器起飞和着陆安全的重要因素,利用多普勒天气雷达径向速度数据,从风的空间和时间变化上对低空风切变的识别进行了研究,并利用一次飑线过程和一次低空急流过程的资料对识别算法进行了验证。识别算法的核心是分别计算二维合成风切变、垂直风切变和时间风切变。在计算二维合成风切变时,先利用风切变强度因子自适应地选择拟合"窗口"的大小,再利用最小二乘线性拟合方法,得到水平风切变。结果表明:自适应多尺度最小二乘法得到的合成风切变,在低空风切变识别效果、切变连续性和边缘数据处理等方面都优于我国多普勒天气雷达的PUP合成风切变;垂直风切变反映了雷达径向速度的高低空配置情况;时间风切变可提供径向速度随时间的变化情况。算法还可应用于民航机场低空风切变的识别和预警。Low-level wind shear is a serious threat to flight safety during the take-off and landing phases. This paper studies the recognition of spatiotemporal low-level wind shear by using radial velocity data from a Doppler radar, and verification is made according to a squall line event and a low-level jet event. The main idea of the recognition algorithm is to calculate two-dimensional wind shear combination, vertical wind shear and temporal wind shear. To get the two-dimensional wind shear combination, an adaptive fitting "window" according to the wind shear intensity factor should be firstly determined, and the least squares linear fitting technique is then adopted within the “window”. The results show that the adaptive multi-scale least squares wind shear combination is better than that of PUP provided by Doppler weather radar system. The advantage is reflected on wind shear detect effect, shear continuity and the outer edge “false” shear. Vertical wind shear refers to the speed variation between two adjacent elevations, and temporal wind shear refers to the speed change with time. The recognition algorithm and results can provide reliable information for airport service and early warning on low-level wind shear.

关 键 词：大气探测 低空风切变 最小二乘法 多普勒天气雷达 合成风切变 垂直风切变 时间风切变 

分 类 号：P412.25[天文地球—大气科学及气象学]