We investigate the speckle effect in atmosphere Lidar returns. Temporal developing speckle patterns in the receiver plane are simulated. The atmospheric model behind this simulation divides the atmosphere into small slices. The contribution from each slice to the field at a particular point in the receiver plane is a sum over a large number of contributions and can be replaced by a Gaussian distributed random number of appropriate variance.
"Speckle patterns in lidar wind measurements from space", Proc. SPIE 3583, Fifth International Symposium on Atmospheric and Ocean Optics, (13 January 1999); doi: 10.1117/12.337040; https://doi.org/10.1117/12.337040