This paper has examined the performance of free space optic system and scattering effects over the laser propagation. Analysis result based on Optisystem simulation software and rain data collected from Malaysia Meteorological Department Perlis, which covering beneath the tropical rainforest weather. The measurement in a simulation using the real parameter from Laserbit system which using wavelength 785 nm, 0.5-15mrad beam divergence, 70mW laser power and range between 100m-2500m. The result can estimate the intensity of rain to impair the link and alternative method to overcome the drawback system.
