星地光通信链路大气湍流衰落特性研究

摘要

The fade statistics of satellite-to-ground laser link is modeled for the gamma-gamma distribution of the irra-diance scintillation subjected to atmospheric turbulence. Probability of fade,mean fade number and mean fade time's statistical characteristic is researched. The analysis is done with different zenith angle. The result of research shows: both decreasing zenith angle and increasing detection sensitivity of receiver can reduce probability of fade and mean fade number evidently,but only shorten a little of mean fade time,and the mean fade time of satellite-to-ground laser link is on the order of milliseconds.%针对大气湍流中gamma-gamma分布的光强起伏,建立了星地光链路的衰落统计模型,研究了不同天顶角星地光通信链路的衰落概率、平均衰落次数及平均衰落时间等关键参数的统计特性.结果表明:减小天顶角和提高接收端探测灵敏度均可以极大的减少衰落概率和平均衰落次数,而不能显著缩短平均衰落时间,星地光链路的平均衰落时间为毫秒量级.