Scintillation of a tracked Gaussian beam for ground-to-satellite laser communication

Recent researches have revealed that, for a tracked uplink Gaussian beam, the scintillation index predicted by the weak fluctuation theory is significantly different from that of the numerical wave optics simulation method when the size of the transmitter aperture is large. In this paper, turbulence-induced scintillation index and the probability distribution of fluctuating irradiance for a tracked uplink Gaussian beam are studied using numerical wave optics simulation method. The simulated data show that in the discrepancy region between the weak fluctuation theory and the numerical simulation method, the simulated fluctuating irradiance is not governed by the generally accepted lognormal distribution even when the weak fluctuation condition is still satisfied.