Fig. 1. The distribution of low frequency samples

Fig. 2. Scaled spectral models of refractive-index fluctuations

Fig. 3. The samples distribution of modified atmosphere spectrum

Fig. 4. A realization of simulated phase screen

Fig. 5. The structure functions of phase screens generating by different method vs. theoretical structure functions

Fig. 6. Beam irradiance distributions in weak and strong fluctuation levels

Fig. 7. Simulated long-term beam width

Fig. 8. Simulated short-term beam width

Fig. 9. Simulated beam-wander standard deviation