turbulent fluxes in the atmospheric boundary layer are calculated using different models. one of the most popular and operational models in this groundwork is the second order turbulent model of mellor and yamada that has been widely used to simulate the planetary boundary layer (pbl). despite its popularity, it has been shown that this model has several weeknesses that affect its accuracy. the...

III Lincoln Laboratory recently completed the three-year Short-Wavelength Adaptive Techniques (SWAT) field program, designed to investigate the performance of adaptive optics in a variety of scenarios. This article describes the operation of the SWAT adaptive optics system working with cooperative beacons. Examples are presented of system operation in compensating star images and in propagating...

Stably stratified turbulence presents particular challenges both from an experimental and a modeling perspective. The damping of the turbulence due to flow stratification and the presence of features such as gravity waves, and Kelvin-Helmholtz instabilities complicate the the application of turbulence similarity theories and the formulation of turbulence models. From an LES perspective, the mai...

We present a method to enhance the quality of a video sequence captured through a turbulent atmospheric medium. Enhancement is framed as the inference of the radiance of the distant scene, represented as a “latent image,” that is assumed to be constant throughout the video. Temporal distortion is thus zero-mean and temporal averaging produces a blurred version of the scene’s radiance, that is p...

In this paper we coipare the theoretical performances of two schemes of optical communication through the atmospheric turbulence: (1) heterodyne detection and (2) video detection. The signal-to-noise ratios (S/N) in the output current of a detector are expressed for both schemes in terms of the correlation function of the refractive index fluctuations of the turbulence. The results of a separat...

Free-space optical (FSO) communication offers significant technical and operational advantages such as higher bandwidth capacity, robustness to electromagnetic interference, a high degree of spatial confinement (bringing virtually unlimited reuse and inherent security), low power requirements, and unregulated spectrum. FSO communication can be deployed as an efficient solution for a wide range ...