Related papers: Local Turbulence: Effects and causes
We have designed a simple multi-scale method that identifies turbulent motions in hydrodynamical grid simulations. The method does not assmume ant a-priori coherence scale to distinguish laminar and turbulent flows. Instead, the local mean…
Metrewave solar type-III radio bursts offer a unique means to study the properties of turbulence across the coronal heights.Theoretical models have shown that the apparent intensity and size of the burst sources evolve at sub-second scales…
Turbulence plays a major role in the formation and evolution of molecular clouds. The problem is that turbulent velocities are convolved with the density of an observed region. To correct for this convolution, we investigate the relation…
Atmospheric turbulence generally limits free-space optical (FSO) communications, and this problem is severely exacerbated when implementing highly sensitive and spectrally efficient coherent detection. Specifically, turbulence induces power…
Context. Future X-ray observatories with high spectral resolution and imaging capabilities will enable measurements and mappings of emission line shifts in the intracluster medium (ICM). Such direct measurements can serve as unique probes…
A six-night optical turbulence monitoring campaign has been carried at Cerro Paranal observatory in February and March, 2023 to facilitate the development and characterisation of two novel atmospheric site monitoring instruments - the…
We present first results of a new instrument, the Generalized Differential Image Motion Monitor (GDIMM), aiming at monitoring parameters of the optical turbulence (seeing, isoplanatic angle, coherence time and outer scale). GDIMM is based…
A characterization of the optical turbulence vertical distribution and all the main integrated astroclimatic parameters derived from the CN2 and the wind speed profiles above Mt. Graham is presented. The statistic includes measurements…
Transition to turbulence dramatically alters the properties of fluid flows. In most canonical shear flows, the laminar flow is linearly stable and a finite-amplitude perturbation is necessary to trigger transition. Controlling transition to…
The development of a quantum network relies on the advances of hybrid systems which includes ground to ground communication. However, the atmospheric turbulence of the environment poses a severe challenge to the optical quantum link. In…
2D and 3D numerical simulations with the adaptive mesh refinement Eulerian radiation-hydrocode RAGE are used to investigate hydrodynamic disruption of asymmetrically driven ICF implosions. A central aspect of this phenomenon is the…
Laser guide stars with adaptive optics allow astronomical image correction in the absence of a natural guide star. Single guide star systems with a star created in the earth's sodium layer can be used to correct the wavefront in the near…
We analyze a set of bidirectional wave experiments in a linear wave flume of which some are conducive to integrable turbulence. In all experiments the wavemaker forcing is sinusoidal and the wave motion is recorded by seven high-resolution…
Intelligent scheduling of the sequence of scientific exposures taken at ground-based astronomical observatories is massively challenging. Observing time is over-subscribed and atmospheric conditions are constantly changing. We propose to…
A novel approach is presented in this paper to improve images which are altered by atmospheric turbulence. Two new algorithms are presented based on two combinations of a blind deconvolution block, an elastic registration block and a…
Several types of Wavefront Sensors (WFS) are nowadays available in the field of Adaptive Optics (AO). Generally speaking, their basic principle consists in measuring slopes or curvatures of Wavefront Errors (WFE) transmitted by a telescope,…
Adaptive optics (AO) systems using tomographic estimation of three-dimensional structure of atmospheric turbulence requires vertical atmospheric turbulence profile, which describes turbulence strength as a function of altitude as a prior…
The site survey for the Advanced Technology Solar Telescope concluded recently after more than two years of data gathering and analysis. Six locations, including lake, island and continental sites, were thoroughly probed for image quality…
We present long term site testing statistics obtained at Dome C, Antarctica with various experiments deployed within the Astroconcordia programme since 2003. We give values of integrated turbulence parameters in the visible at ground level…
We report experiments on the full space and time resolved statistics of capillary wave turbulence at the air-water interface. The three-dimensional shape of the free interface is measured as a function of time by using the optical method of…