Laser beam propagation in random media : new and advanced topics This research monograph is a companion edition and update to the book: L. C. Andrews and R. L. Phillips Laser Beam Propagation through Random Media 2nd edition (SPIE Press 2005). We present several new and advanced topics that have emerged during the years since the 2005 title was published. Much of the new material is compared throughout the text with experimental and computer simulation data. This comparison includes beam wander and its effect on a propagating laser beam including beam wander induced scintillation. Other additions include an assessment of conventional probability density function (PDF) models for the irradiance after passing through a finite receiver aperture. New mathematical models for enhanced backscatter are introduced here including extension to strong fluctuation regimes and semi rough targets. In recent years scientists have found experimental evidence that non Kolmogorov and anisotropic conditions may occur even along horizontal propagation paths near the ground. We include a chapter on these important topics that presents a detailed treatment involving both non Kolmogorov and anisotropic models. The book ends with a chapter devoted to the discussion of commonly used instruments for measuring atmospheric parameters like the refractive index structure parameter inner scale temperature wind speed heat flux and so forth