Measurements of the wavefront outer scale at Paranal: influence of this parameter in interferometry

Rodolphe Conan; Aziz Ziad; Julien Borgnino; Francois Martin; Andrei A. Tokovinin

doi:10.1117/12.390176

5 July 2000 Measurements of the wavefront outer scale at Paranal: influence of this parameter in interferometry

Rodolphe Conan, Aziz Ziad, Julien Borgnino, Francois Martin, Andrei A. Tokovinin

Proceedings Volume 4006, Interferometry in Optical Astronomy; (2000) https://doi.org/10.1117/12.390176
Event: Astronomical Telescopes and Instrumentation, 2000, Munich, Germany

Abstract

The Generalized Seeing Monitor (GSM) has undertaken a campaign of measurement of the optical turbulent parameters: the Fried's parameter, the outer scale (L₀) and the isoplanatic patch, at Paranal, the site of the VLT, in December 1998. The principle aim of this mission was to measure L₀ values at Paranal. In a first part, we present the GSM, the results of the mission and particularly the statistics of L₀. In a second part, we emphasize the effect of L₀ on the optical path difference (OPD) values for the co-phasing of an interferometer. We derive the exact formulation of the OPD for the Von Karman model and we give the expected OPD at Paranal with L₀ values measured by the GSM. We give also the expression of the residual OPD at the output of a fringe tracker system as a function of L₀, of the exposure time of the fringe sensor and of the frequency of the closed-loop of the system.

Citation Download Citation

Rodolphe Conan, Aziz Ziad, Julien Borgnino, Francois Martin, and Andrei A. Tokovinin "Measurements of the wavefront outer scale at Paranal: influence of this parameter in interferometry", Proc. SPIE 4006, Interferometry in Optical Astronomy, (5 July 2000); https://doi.org/10.1117/12.390176

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available