星地光通信地面站空间分集技术研究

通过建立星地光链路模型对地面站空间分集技术中站址的选择、站址间距离以及地面站数量进行研究，结果表明:站址的合理选择可以提高星地链路的可用性；站址间的距离在保证各站天气不相关的同时不能过大，当站址间距离与卫星高度的比值达到1时，由链路天顶角增大带来的衰减高达10 dB以上；单地面站的可用性越高，所需的地面站数也越少，当单站的可用性达到0.6时，只需3个地面站即可达到与射频链路相当的高可用性。

Ground station-s space diversity technology for satellite-to-ground optical communication

The choice of stations address, interval and number of stations in ground stations space diversity technology is investigated by modeling optical link for satellite-to-ground optical communication. The result of research shows, reasonable choice of stations address can improve the availability of satellite-to-ground optical communication link; the interval of stations should ensure the weathers at different stations are uncorrelated but not too long; the attenuation resulted from zenith angle is more than 10 dB when the ratio of interval and altitude of satellite is larger than 1; the necessary amount of stations is smaller if the availability of single ground station is higher; only 3 stations are needed with equivalent availability of microwave link when the availability of single station is 0.6.