晴朗无云天空光谱辐射的近似计算模型

 利用大气光学质量和大气气溶胶光学厚度的经验公式，由HITRAN数据库获得大气分子谱线参数，基于辐射传输方程，给出了晴朗无云天空光谱辐射的近似计算模型。根据该近似计算模型对晴朗无云天空光谱辐射亮度进行的计算结果表明：天空光谱辐射亮度曲线上存在明显的O₂和H₂O吸收线；晴朗无云天空辐射的光谱分布偏蓝，天空亮度主要集中在短波段部分；太阳角小的天空光谱亮度出现“红移”现象；由于大气厚度变大，近地平的天空辐射亮度较大。

Approximate computation modal of clear sky spectral luminance

Based on radiative transfer equation, using the experiential formulae of air mass and atmospheric aerosol optical depth and atmospheric molecule parameters obtained by HITRAN database, an approximate algorithm for clear sky spectral luminance was given, which could be used generally. Clear sky spectral luminance was computed by the approximate algorithm model. Computation results indicate that there are distinct absorption lines of O2 and H2O on the curve of clear sky spectral luminance. The luminance of clear sky radiation is higher at shortwave band, while the spectrum for small sun angle shifts to longer waveband. The sky radiation luminance adjacent to horizon is higher.