Statistical properties of single-mode fiber coupling of satellite-to-ground laser links partially corrected by adaptive optics

In the framework of satellite-to-ground laser downlinks, an analytical model describing the variations of the instantaneous coupled flux into a single-mode fiber after correction of the incoming wavefront by partial adaptive optics (AO) is presented. Expressions for the probability density function and the cumulative distribution function as well as for the average fading duration and fading duration distribution of the corrected coupled flux are given. These results are of prime interest for the computation of metrics related to coded transmissions over correlated channels, and they are confronted by end-to-end wave-optics simulations in the case of a geosynchronous satellite (GEO)-to-ground and a low earth orbit satellite (LEO)-to-ground scenario. Eventually, the impact of different AO performances on the aforementioned fading duration distribution is analytically investigated for both scenarios

N° 56. — Enthalpie de la transition « tetragonale-cubique » des céramiques ferroélectriques aux titanates mixtes de baryum et de strontium

Par un procédé de microanalyse différentielle, les variations d’enthalpie des transitions tétragonale-cubique de solutions solides ferroélectriques (Ba, Sr) TiO3 ont été déterminées avec précision. Les énergies de transformation semblent essentiellement liées aux variations de volume des mailles cristallines

Le baptême du p'tit Gaga : chansonnette / paroles de Péricaud et Blondelet ; musique de Alb. Petit et Grim ; créée par Melle Valti

Collection : Nouveau répertoire des concerts de Paris ; 1

Numerical investigation of the relative effect of disc bulging and ligamentum flavum hypertrophy on the mechanism of central cord syndrome

International audienc

Tensile mechanical properties of the cervical, thoracic and lumbar porcine spinal meninges

International audienc