title: Method of estimating time scales of the atmospheric piston and its application at Dome C (Antarctica).
abstract: Analysis of the first interferometric fringes recorded at Dome C, Antarctica are presented. Measurements were taken 31 January and 1 February 2005 during daytime. Our purpose in performing the analysis was to measure temporal fluctuations of the atmospheric piston, which are critical for interferometers, and determine their sensitivity. These scales are derived through the motion of the image that is formed in the focal plane of a Fizeau interferometer. We could establish a lower limit to the coherence time by studying the decay rate of correlation between successive fringes. Coherence times are measured to be larger than 10 ms, i.e., at least three times higher than the median coherence time measured at the site of Paranal (3.3 ms).
authors.affiliation: European Southern Observatory, Karl-Schwartzchild-Strasse 2, D-85748 Garching bei Munchen, Germany. akellere@eso.org
authors.forename: Aglae
authors.initials: A
authors.lastname: Kellerer
authors.forename: Marc
authors.initials: M
authors.lastname: Sarazin
authors.forename: Vincent Coudé
authors.initials: VC
authors.lastname: du Foresto
authors.forename: Karim
authors.initials: K
authors.lastname: Agabi
authors.forename: Eric
authors.initials: E
authors.lastname: Aristidi
authors.forename: Tatyana
authors.initials: T
authors.lastname: Sadibekova