基于统计置信度的湍流检测门限确定方法

Method for Setting Threshold of Turbulence Detection Based on Statistical Confidence Level

机载气象雷达是检测飞行中湍流的重要设备,对于保障飞行的安全具有重大意义。它通过判断回波信号谱宽是否超过门限来检测湍流,关键在于检测门限的设定。将其看成一个统计问题进行解决,提出了利用统计学中置信度来设置门限的方法,根据湍流微粒的概率分布推导了置信度与检测门限的关系,并利用其进行检测门限设置。最后利用仿真的气象雷达回波信号进行了实验,实验结果表明提出的方法能够检测出实验中设置的湍流区域,验证了方法的有效性。

Airborne weather radar is a key equipment to detect the turbulence existing in the flight path,which is very important for aviation safety. The weather target with the spectrum width of the echo exceeding the detection threshold is classified as turbulence,so the key to detect turbulence is threshold＇s setting. A statistical model of the problem is established and a threshold setting method based on statistical confidence level is presented in this paper. According the velocity distribution characteristics of turbulent particles ,the relation between the confidence levels and threshold is derived. Then it is used to set the threshold for acquiring the defined confidence level. The detection results with simulated weather signal demonstrate that the located three turbulent areas in simulated scene are detected successfully, so it is effective.