Scintillation Index of a Plane Wave Propagating Through Kolmogorov and Non-Kolmogorov Turbulence along Laser-Satellite Communication Downlink at Large Zenith Angles

Abstract

Under the background that the Earth’s aerosphere contains Kolmogorov and non-Kolmogorov turbulence, it is significant to research the combined influence of these two kinds of atmospherical turbulence on laser-satellite communication. In this paper, based on the power spectra of refractive-index fluctuations for non-Kolmogorov turbulence in the free troposphere and stratosphere, using the extended Rytov theory, the scintillation indices of the spherical wave in the free troposphere and the stratosphere are derived, respectively, which are valid in all regimes of turbulent fluctuations. On this basis, using a three-layer altitude-dependent turbulent spectrum model for vertical/slant path describing the variations of turbulent statistical characteristics with altitude in the aerosphere, which is more accurate than the two-layer model, we present the scintillation index of a spherical wave propagating through Kolmogorov and non-Kolmogorov turbulence along laser-satellite communication uplink at large zenith angles and estimate the combined influence of Kolmogorov and non-Kolmogorov turbulence on the scintillation index. It is noteworthy that this expression is also valid in all regimes of turbulent fluctuations.