湿度起伏对可见光折射率结构常数影响的实验研究

Experimental Study of Effects of Humidity Fluctuation on the Refractive Index Structure Parameter for Visible Radiation

利用合肥郊区夏季三维超声风速计测量的虚温、风速和Li7500二氧化碳和水汽分析仪获得的水汽浓度资料,从两个方面研究湿度起伏对三维超声风速计测量可见光折射率结构常数C2n的影响。对超声虚温进行湿度修正后,得到真实温度,比较了由超声虚温和真实温度分别计算得到的温度结构常数C2T。另一方面,计算出温湿度相关项CTq和湿度结构常数C2q各自对C2n的贡献。结果显示真实温度计算得到的C2T与超声虚温计算得到的C2Ts有显著差别,很多时候两者的差异超过10%。CTq对C2n的贡献较大,可超过10%,不可忽略;而C2q对C2n的贡献很小,普遍低于5%,可以忽略。

Based on the virtual temperature, wind speed and H2O concentration data respectively measured by the sonic anemometer and Li7500 CO2/H2O analyzer sensor in the summer of Hefei, the effects of humidity fluctuation on the measurement of the refractive index structure parameter C2n for visible radiation by sonic anemometer from two aspects are studied. The real temperature from virtual temperature via humidity corrections is obtained. Temperature structure parameter C2T respectively calculated via real temperature and virtual temperature is compared. In the other side, the contributions of humidity structure parameter C2q and temperature-humidity correction CTq on C2n are calculated. The results show that the distinction between C2T calculated via real temperature and virtual temperature is obvious, and the difference is more than 10% most of the time. The contribution of CTq can be more than 10%, and it can′t be ignored. The contribution of C^2q is extraordinarily small, lower than 5%, and it can be ignored.