Mitigating Atmospheric Effects on Space-to-Ground Optical Communication: Insights from Channel Characteristic Analysis

Space-to-ground optical communication has emerged as a critical development direction for future communication systems, owing to its advantages of a high bandwidth, strong confidentiality, and immunity to electromagnetic interference. However, its practical deployment is significantly restricted by the severe degradation of laser transmission performance induced by random atmospheric channels. To address this bottleneck, this paper systematically analyzes the vertical distribution and composition of the atmosphere, and identifies the core parameters that characterize fundamental atmospheric properties. On this basis, we focus on the key influence mechanisms of atmospheric channels in space-to-ground optical communication. The effects of atmospheric absorption, attenuation, scattering, and turbulence on laser signals are investigated, and corresponding mathematical models are established to quantify their influence laws. Simulation results validate the effectiveness of the theoretical models and show that atmospheric transmittance varies considerably under different weather conditions. In specific atmospheric environments, the rational selection of communication wavelengths, the optimal configuration of the zenith angle for ground terminals, and the appropriate design of system height play decisive roles in ensuring stable and efficient signal transmission for space-to-ground optical communication.