气象探空火箭测风不确定度评估方法

本文在气象火箭测风反演数学模型基础上,通过误差分析理论和曲线拟合最小二乘原理,对大气风场反演结果不确定度的评估方法进行了研究。根据火箭探空仪在空中的运动规律,首先建立数学反演模型,推导得到风速和风向的计算公式;然后根据误差理论,推导得出反演风速和风向的不确定度表达式;基于多项式拟合方法,进一步推导得出拟合后的风速和风向的系统误差和随机误差公式,并求解公式中系数。最后以1次气象火箭实测数据为例,对风场及其不确定度进行了分析计算。结果表明:风速反演不确定度随高度降低而减小,在50~60km高度不确定度约为2.8~3.5m/s,50km以下不确定度在1m/s以内;风向在正北方向(0°)附近摆动时,会导致反演不确定度异常增大,其他高度不确定度基本在10°以内。

Method for Evaluating Uncertainty of Wind Measurements for Meteorological Sounding Rocket

Based on the inversion model of wind measurement for meteorological rockets, the method for evaluating the uncertainty of wind inversion results is studied by the error theory and curve fitting least square principle. According to the motion law of the rocket sonde in the air, a mathematical model is established and the inversion function of wind speed and wind direction is derived. According to the error theory, the general expressions of the uncertainty of wind speed and wind direction are given. Based on the principle of polynomial least square fitting, the formulas of the systematic error and random error of wind speed and direction are derived, and the coefficients in the formulas are obtained. Taking the measured data as an example, the above formulas are used to analyze and calculate the atmospheric wind and the uncertainty. The results show that the uncertainty of wind speed decreases with the decrease of height. The uncertainty is 3.5 to 2.8 m/s in the 60 to 50 km, and less than 1 m/s below 50 km. When the wind direction is around the north (0°), the inversion uncertainty of wind direction will increase abnormally, and the inversion uncertainty is basically within 10° in the other cases.