Long wave infrared transmission in atmospheric channel

A free space optical communication channel model including stochastic transfer distance and direction of photon after being scattered was developed using a Monte Carlo simulation method based on photon tracing. In this model, beam divergence and field of view(FOV) were introduced, the influence of scattering was also in consideration. Simulations using Monte Carlo method and Lambert-Beer Law were carried out under fog condition with long wave infrared. Compared with Lambert-Beer Law, the result shows that the received energy of scattering can't be ignored under the condition of short range and low visibility. The influence of different ranges, visibilities, beam divergences and field of views on pass loss were analysed respectively using Monte Carlo method. The contributions of different scattering orders to total received energy were also illustrated. The effects caused by the 4th or higher orders scattering can be overlooked under given conditions so as to improve the efficiency of calculation.