Article de Vulgarisation
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We report the observations of the clear-sky fraction at the Concordia station during winter 2006 and derive from it the duty cycle for the astronomical observations. The duty cycle and observation duration at Dome C allow for efficient asteroseismic observations. This performance is analyzed and compared to network observations. For network...
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In a first part of the paper we give a simple introduction to the free space propagation of light at the level of a Master degree in Physics. The presentation promotes linear filtering aspects at the expense of fundamental physics. Following the Huygens-Fresnel approach, the propagation of the wave writes as a convolution relationship, the...
During the austral winter 2005, the first astronomical site testing campaign were performed at Dome C, in Antarctica. Thirty-five meteorological balloons equipped with microthermal sensors were used to sense the vertical profile of the optical turbulence intensity above Dome C up to 20 km. All the profiles of the 2005 campaign are statistically...
Dome C in Antarctica is a particular astronomical site when considering the optical turbulence conditions. From the first winterover campaign performed in 2005 at Dome C, the set of 34 meteorological balloon profiles has been analyzed. The meteorological balloons were equipped with microthermal sensors used to sense the vertical profile of the...
This paper describes a comparison between balloon radio-soundings made in summer at the Concordia station, Dome C, Antarctica and coincident model-based meteorological analyses. The comparison allows the assessment of the reliability of the analyses in summer. This allows the use of the winter analyses within an estimated range of uncertainty,...
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For the detection and direct imaging of exoplanets, when the intensity ratio between a star and its orbiting planet can largely exceed 106, coronagraphic methods are mandatory. In 1996, a concept of achromatic interferocoronagraph (AIC) was presented by J. Gay and Y. Rabbia for the detection of very faint stellar companions, such as exoplanets....
Abstract The performance of ground-based astronomical observations and free-space optical communication (FSOC) systems suffers from atmospheric turbulence and meteorological conditions. The a priori knowledge of atmospheric conditions several hours before observations allows the programming of astronomical observations (flexible scheduling) to...
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The effect of atmospheric turbulence on the imaging of scenes, for an horizontal propagation of the light over a distance of 20 km, 15 meters above the sea surface, was analyzed at visible wavelength using a 20 cm telescope. Point-sources images were recorded during the night, and the Fried parameter r 0 was derived leading to values ranging...
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