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Last name: ZIAD
First name: A.
Towards atmospheric turbulence outer scale profiler, n/a n/a, (2005)
Workshop : The Thirty Meter Telescope (TMT) Site Testing, n/a n/a, (2005)
n/a, n/a n/a, p. n/a (2005)
The optical turbulence forecasting has become a necessary information for an optimal programmation of the astronomical observations, called "flexible scheduling". We propose the prediction of the optical turbulence by means of the Weather Research and Forecasting (WRF) model combined with an optical turbulence model. We performed a set of...
PASP, 117, pp. 395-400 (2005)
Proceedings of the Symposium on Seeing, n/a, pp. 26-28 (2007)
Proceedings of the Symposium on Seeing, n/a, pp. 31-36 (2007)
Conference OSA - Adaptive Optics : Analysis and Methods Meeting, n/a, (2007)
MNRAS, 377, pp. 1236-1244 (2007)
To reach a high performance with an adaptive optics system, we need a calibration using a reference source. This latter should be located in the same isoplanatic domain as the science source. Different techniques and methods have been developed leading to estimations of the isoplanatic patch but all are model-dependent. We developed a new...
International audience
International audience
We present a reanalysis of several years of DIMM data at the site of Dome C, Antarctica, to provide measurements of the coherence time τ 0. Statistics and seasonal behaviour of τ 0 are given at two heights above the ground, 3m and 8m, for the wavelength λ = 500nm. We found an annual median value of 2.9ms at the height of 8m. A few measurements...
International audience
Advances in Stellar Interferometry, eds. J. D. Monnier, M. Schöller and W. C. Danchi, SPIE 6268, (2006)
A new method is proposed for the verification of the atmospheric turbulence model. It is based on the reconstruction of the phase structure function from simultaneous measurements of the Angle-of-Arrival longitudinal covariance at different baselines with the Generalized Seeing Monitor (GSM). In addition, with this new technique we obtain the...
n/a, Società Astronomica Italiana Publication 2, p. 146 (2003)
The first astronomical seeing monitoring has been made with a DIMM instrument at the Antarctic plateau site of Dome C in December, 2002 on the bright star Canopus (alpha Eri) during the daytime. In these far from optimal conditions, a median seeing of 1.2 arcsec as been obtained, with extended periods better than 1 arc-sec and 12 percent of the...
Astron. & Astrophys., 406, pp. L19-L22 (2003)
The HAR observing methods such as Adaptive Optics and Interferometery, require a better understanding of the behavior of the perturbed wavefronts, more exactly a better knowledge of the atmospheric turbulence model in addition to the associate parameters. This is very crucial for modeling the HAR techniques and particularly for the evaluation...
The first astronomical seeing monitoring has been made with a DIMM instrument at the Antarctic plateau site of Dome C in December, 2002 on the bright star Canopus (α Eri) during the daytime. In these far from optimal conditions, a median seeing value of 1.20 arcsec as been obtained, with extended periods better than 1 arcsec and 12 percent of...
The first astronomical seeing monitoring has been made with a DIMM instrument at the Antarctic plateau site of Dome C in December, 2002 on the bright star Canopus (α Eri) during the daytime. In these far from optimal conditions, a median seeing value of 1.20 arcsec as been obtained, with extended periods better than 1 arcsec and 12 percent of...
The optical turbulence measurement and characterization has become an essential information for optical link (telecommunication, telemetry, time transfert, ...) and for high-angular resolution imagining in astron- omy. For example, it has an impact on the quality and on the bit error rate of optical communication signals and it decrease the...