Hai-Yang Fu

This study presents a dynamic satellite-ground quantum key distribution (QKD) model that incorporates time-evolving turbulence with a complete optical stack, including diffraction, atmospheric influence, tracking system, fiber coupling, and the background noise. And the finite key performance of BB84 protocol is estimated using time-resolved losses and noises. Results shows a GEO-to-Lijiang link can still deliver 20–117 kbit per 10¹² pulse under strong turbulence during the night, and the parameters scan identify diffraction-dominated attenuation—not background noise—is the chief bottleneck. The study evaluates the secret key rate under different atmospheric and temporal conditions, offering insights into optimizing satellite-ground QKD systems for practical use.