BORGNINO , Julien

The theoretical expression of the transverse angular covariance of angle-of-arrival fluctuations of the incoming wave-fronts integrated all over the telescope pupil has been established in the case of one-layer model and using the Von Kàrmàn theory. This model depends on three atmospheric parameters: the spatial coherence outer scale ${\cal...

Anisoplanatism in Adaptive Optics or Differential Astrometry as in ground-based solar diameter measurement needs the knowledge of atmospheric turbulence profiles. MISolFA is a monitor dedicated to statistically estimate daytime turbulence profiles C-{n}**{2}(h) from solar limb agitation measurements. In order to understand the statistics of the...

Seeing monitoring in astronomy is widely based on the statistical analysis of angle-of-arrival (AA) fluctuations, which are usually modelled in the framework of the near-field approximation where diffraction through turbulence is ignored. They are consequently believed to be completely independent of wavelength. We discuss in this paper the...

Atmospheric turbulence is responsible of spatio-temporal fluctuations of astronomical object images obtained by means of ground-based telescopes. The image motion is due to the angle formed by the pupil plane with the wave-front slope all over the pupil. This defines an averaged angle of arrival which may be also considered at each point of the...

High angular resolution observations of the sun are limited by atmospheric turbulence. The MISOLFA seeing monitor (still under construction) is developed to obtain spatial and temporal statistical properties of optical turbulence by analyzing local motions observed on solar edge images. The solar flying shadows used for angle-of-arrival...

A method is presented allowing one to estimate, in the case of daytime observations, the angle-of-arrival isoplanatic patch size from the measurement of the differential image motion of the solar limb. The experimental results have been obtained using the solar astrolabe of Calern Observatory (CERGA-France). Performing a modelization as...

In order to deduce significant astrophysical results from solar diameter measurements it is necessary to take an accurate account of instrumental and atmospheric effects. This paper presents a comparison between visual and charge coupled device (CCD) camera measurements performed by means of the Calern Observatory solar astrolabe during the...

High angular resolution observations of the sun are limited by atmospheric turbulence. The MISOLFA seeing monitor (still under construction) is developed to obtain spatial and temporal statistical properties of optical turbulence by analyzing local motions observed on solar edge images. The solar flying shadows used for angle-of-arrival...

Atmospheric turbulence is responsible of the spatio-temporal fluctuations in astronomical object images obtained by means of ground-based telescopes. They are due to wave-front degradations present at the entrance of the instrument pupil plane. We first establish in this paper the formulation of the angle-of-arrival angular structure function...

The MISOLFA seeing monitor is developed to analyze spatial and temporal statistical properties of daytime optical turbulence. It is based on Angle-of-Arrival (AA) statistical properties. The MISOLFA optical de- vice measures AA-fluctuations observed as intensity variations in the pupil plane image formed through a thin slit positioned in the...