  A new scaling law model for propagation of optical beams through atmospheric
turbulence is presented and compared to a common scalar stochastic waveoptics
technique. This methodology tracks the evolution of the important beam
wavefront and phasefront parameters of a propagating Gaussian-shaped laser
field as it moves through atmospheric turbulence, assuming a conservation of
power. As with other scaling laws, this Lagrangian scaling law makes multiple
simplifying assumptions about the optical beam in order to capture the
essential features of interest, while significantly reducing the computational
cost of calculation. This Lagrangian scaling law is shown to reliably work with
low to medium turbulence strengths, producing at least a 2x computational
speed-up per individual propagation of the beam and >100x memory reduction
(depending on the chosen resolution).
