湿度起伏对可见光波段C_n^2影响的再研究

Reinvestigation of Humidity Fluctuation Influence on C_n^2 in Visible Range

用Li7500 CO_2/H_2O分析仪直接测量了近海边湿度起伏数据,结合温度脉动仪和超声风速计测量的数据,计算出湿度、温度和温湿相关项的结构常数,研究了湿度起伏对C_n^2的影响。结果表明:对于可见光,相对于温度起伏而言,湿度起伏和温湿相关项的贡献都很小。实验期间不论是白天还是夜晚,都有与Kolmogorov-5/3谱相近的温度谱和湿度谱存在,并且,在低波数区出现-1次方谱幂率,绝大部分湿度谱幂率值处于-5/3±0．2的区间内。

Humidity fluctuation data in damp sea shore were directly measured by Li7500 CO2/H2O analyzer. Temperature fluctuation was measured by three component sonic anemometers. Utilizing these data, structure parameters Ct^2, Ctq, Cq^2 were computed and then effects of humidity fluctuation on the structure parameter of the refractive index were reinvestigated. Results showed, for visible range, both humidity effects and temperature-humidity correlation term effects on Cn^2~ is obviously less than temperature effects. At daytime as well as at night, there are temperature and humidity spectrum which follows Kolmogorov -5/3 law over inertial range during experiment, moreover, the spectrum power -1 is presented at low wavenumber range, most values of the humidity spectrum power are between -5/3 - 0.2 and -5/3 ＋ 0.2.