Ground equivalent verification for atmospheric turbulence effects on fiber-coupling efficiency of satellite-to-ground downlink

The fiber-coupling efficiency of a satellite-to-ground (STG) downlink laser communication system is particularly influenced by atmospheric turbulence, thereby reducing the communication performance significantly. We report on a highly reliable ground equivalent verification to demonstrate the atmospheric turbulence effects on the fiber-coupling efficiency of an STG downlink. Statistical distribution of fiber-coupling efficiency obtained by experiment contributes a high consistency with the numerical simulation, with a correlation coefficient of above 0.97. The average deviation of fiber-coupling efficiency is only around 10% according to different trials on the course of ground equivalent verification. Ground equivalent verification provides a way to study the actual STG downlink with a smaller diameter of aperture, which might also potentially be a great help to serve on an experimental basis and reference for the optimal design of the STG downlink laser communication systems.