在光电扫描系统中,热晕驻区会对激光大气传输能量产生严重的衰减,而热晕驻区出现的概率是由大气 风速风向联合概率决定的。由合肥地区2007年5月至2011年6月的对流层风廓线雷达1 h平均风场数据,根 据最小二乘法原理,分别拟合Frechet、Gumbel和Weibull概率分布,得到拟合参数及相关系数和剩余标准 差,从而比较得到最优分布模型;在上述方法拟合不出较好结果的情况下,由样本数据,根据圆形正态 概率分布的特点,计算出纬向风和经向风平均值和均方差,这样也可以得到风场概率随风速和风向的 关系,从而计算某一风场对应的概率。

In photoelectricity scanning system, stagnation zoon of thermal blooming makes energy of laser propagation decrease through atmosphere. The probability of stagnation of thermal blooming is decided by joint probability of wind speed and direction of atmosphere. Based on the wind profile radar one hour average wind field data from May 2007 to June 2011, according to the least square method, Frechet, Gumbel and Weibull probability distribution were fitted. The fitting parameters, correlation coefficient and residual standard deviation were obtained. The optimal model was achieved by the comparison of different results. In condition of no good fitting result of above method, based on sample data, according to the characteristics of circular normal probability distribution, zonal wind and meridional wind average value and mean square deviation can be calculated. The relationship of wind field probability varying with wind speed and direction can be obtained so as to obtain probability for some wind field.