Numerical optical wave propagation through the atmosphere incorporating scattering models

Wave optics simulations are a common method of studying the effect of beam propagation through the atmosphere. Current widely-used software utilizes phase screens that are statistically representative of Kolmogorov turbulence where the scattering parameter along the laser path relies on an atmospheric structure parameter which is typically measured using a path averaged scintillometer. While this method works for homogenous atmospheric conditions in which there is little variation between the transmitter and the receiver, in adverse environments such as those with high precipitation rates, heavy fog, or clouds, this method of modeling beam propagation can be insufficient. This work computes scattering from a “first principles” approach, where the full Mie series is calculated at several locations along the simulated beam path. The scattering results are then combined with traditional split-step beam propagation methods resulting in a more-complete, and therefore more-accurate, beam performance model. The simulation results are compared to experimentally measured statistical beam profiles, showing that including scattering models results in a more accurate prediction of performance.