基于自适应多尺度的梯度搜索风切变预警算法研究

The Gradient Search Alerting Algorithm of Low-level Wind Shear Based on Adaptive Scale

新一代多普勒天气雷达(China new generation radar,CINRAD)主要依据单尺度的径向、切向速度梯度或者是两者合成的结果探测风切变,容易产生漏报。针对此问题,提出了基于自适应多尺度的梯度搜索风切变预警算法。该算法的核心思想是进行多个自适应尺度的速度梯度拟合。首先,计算多个尺度下最大风切变强度因子,取较大因子值对应的尺度为自适应尺度。其次,在径向上以自适应尺度进行最小二乘速度梯度拟合。最后,以国际上规定的低空风切变阈值搜索速度梯度,并合并切变段给予预警。采用东北空管局提供的新一代多普勒天气雷达(CINRAD-CD)真实数据进行实验。结果表明新方法能够检测出所有尺度类型的风切变,提高了风切变预警率,具有一定的实际应用价值。

China New Generation Radar use radial and tangential velocity gradient or the result of the combined based on fixed scale to detect wind shear. These methods are easy to cause omission. Aiming at this problem,a new low-level wind shear alerting algorithm based on adaptive scale was presented. The core idea of the algorithm is to calculate the velocity gradient based on several adaptive scales. Firstly,select multiple scale to calculate maximum wind shear intensity factor,choose the scale corresponding to the larger intensity factor value as the adaptive scale.Secondly,do the least squares fitting for many times on the radial. Finally,compare the fitting gradient with provisions of international low-level wind shear threshold and merger them to come to the conclusion. The performance of the proposed method is verified through the real data from The Northeast Flugsicherung,the results show that the proposed algorithm can detecte wind shear of all kinds of scales. Therefore,the proposed method improved the alarm rate. It has a certain practical application value.