Scintillation index of the free space optical channel: Phase screen modelling and experimental results

Scintillation index (SI) is a key metric for free space optical communications (FSOC), and measures the normalised intensity variance caused by atmospheric turbulence. It is a function of the refractive index structure parameter C_n², range, and receiver aperture. There is a need for an atmospheric simulation model of the effects of scintillation because testing of FSOC performance in the environment is difficult and time consuming. In this paper we compare experimental results with numerical simulations using phase screens for channels involving three receivers of different size apertures. There is good agreement in the results of experiment and model.