大口径的地基红外望远镜必须安装在具有良好大气条件的观测台站才能充分发挥其性能, 天空背景辐射和大气传输特性是地基红外望远镜站址选择所需考虑的重要内容。采用消光-小角度散射法在西藏羊八井实测了太阳直接红外辐射和大气背景红外辐射, 并根据备选站点的大气参数, 采用CART软件计算了当地8~14 μm波段整层垂直大气的光谱透过率、太阳直接光谱辐射和地面大气垂直向下的背景光谱辐射, 以及相关量的波段积分值, 这些结果有助于地基红外太阳望远镜的站址选择。

Selecting a fine atmospheric site is very important for ground-based infrared astronomy. The sky background radiance and atmospheric transmittance are important factors for selecting site. Combined observations of solar spectral extinction and forward angular scattering were presented with ground-based FTIR on Yangbajing, Tibet. The direct solar irradiance and atmospheric background radiance were showed on 8-14 μm band. According to the atmospheric parameters, the direct solar radiance, atmospheric spectral transmittance and background radiance of selecting sites were compared by CART on long-wave infrared band. These will be useful to select a site for ground-based infrared solar telescope.