激光通信地面站址的大气信道特性决定着设备性能的有效发挥。 选择四个候选站址,西藏阿里、青海德令哈、四川稻城和河北兴隆,统计检验云量覆盖、 大气透过率、天空辐射度和大气湍流等特征对激光通信的影响。结果显示,单站可用度 条件以阿里为最佳；三站联合可用度以阿里-德令哈-兴隆最好,在少云条件下(云量低于60%)全年可用 度85%以上;少云条件下的四站联合可用度在5～8月为91%～96%,其它月份98%以上。 四个候选站址的大气光学特性均能满足激光通信传输的要求。高海拔站址的大气透过率与辐 射度有明显优势,阿里、稻城的夜间大气相干长度在10 cm以上,德令哈在8～12 cm间, 兴隆站在6 cm以上。在多站联合模式下应能在高海拔的少云区选择出足够高可用度的站址。

The atmospheric channel characteristics of laser communication ground station determine the equipment performance. Four candidate sites, Ali in Tibet, Delingha in Qinghai, Daocheng in Sichuan, and Xinglong in Hebei China, were selected for statistical inspection of the effects on laser communication, including the factors of cloud coverage, atmospheric transmittance, sky background radiation, and atmospheric turbulence. It was shown that Ali is the best for single station availability; Ali-Delingha-Xinglong is the best for the three-station combined availability, more than 85% in full year under 60% cloudiness. For the four stations under 60% cloudiness, the combined availability can be 91%～96% in May to August, and reaches more than 98% in other months. The atmospheric optical properties of the four candidate sites meet requirement of laser communication. The high altitude sites have obvious advantages in atmospheric transmittance and background radiance. The atmosphere coherence length in night is larger than 10 cm in Ali and Daocheng, and 8～12 cm in Delingha, and just higher than 6 cm above for Xinglong. In multi-station combined mode, good sites, with sufficient high availability and meeting optical communication requirements, could be selected in high altitude and less cloud areas.