基于激光测风雷达的两种低空风切变告警算法对比研究

Comparison of Two Lidar-based Alerting Algorithms for Low-level Wind Shear

利用兰州中川国际机场2020年7—11月激光测风雷达观测资料和飞行员报告的12次风切变事件,对比分析单、双斜坡结合检测法和区域散度法两种低空风切变告警算法的应用效果,并与实际业务中的IRIS告警算法监测结果进行对比。结果表明:(1)两种算法对于对流天气或动量下传天气背景下的风切变具有较好的告警能力,但对于湍流背景下的风切变告警能力较弱;(2)相比斜坡检测法,区域散度法采用多个径向重构逆风廓线,在一定程度上能够反映出跑道及其延长线上径向风的时空演变信息,有利于风切变的提前识别和告警;(3)12次风切变事件的告警准确率表明区域散度法优于斜坡检测法和IRIS算法。

Based on the wind lidar observation data and 12 wind shear events reported by pilots at Lanzhou Zhongchuan airport from July to November 2020,the performance and effectivity of two lidar-based low-level wind shear alerting algorithms were investigated.One algorithm is the regional divergence algorithm(RDA),and another is the combinational algorithm of single ramp and double ramps detection.The IRIS algorithm,the default algorithm in the lidar,was used as a reference.The conclusions are as follows:(1)RDA and ramp detection algorithm had better ability in alerting wind shear events under the convection weather or downward momentum weather conditions.However,they had a poor performance on identification of wind shear events under turbulent conditions.(2)Compared with ramp detection algorithm,RDA uses multi-radial directions to reconstruct headwind profile,and consequently it can provide some temporal and spatial evolution information of radial velocities along the runway and its extension line,which is conducive to identification and alerting of wind shear events ahead of time.(3)The alerting results on 12 wind shear events indicated that RDA was superior to ramp detection algorithm and IRIS algorithm.