In the planning stage of extremely large telescopes, site testing and study of high performance adaptive optics systems plays very important roles. Site testing is a very time consuming task, therefore, we have built a fully automatic device - the CUTE SCIDAR instrument with a user-friendly interface and real time processing. This instrument is already in operation and now has been installed in the Jacobus Kapteyn Telescope of Roque de los Muchachos Observatory at La Palma for periodical turbulence profiling. A second version with an additional phase sensor bench contains a motorized field stop, a field lens, a collimator lens, and a Shack-Hartmann sensor. This instrument measures the turbulence from both amplitude and phase variations of the same distorted wave at high frequency bandwidth, with a high resolution and dynamic range. On the one hand, this will solve the calibration problem between different turbulence sensors. On the other hand, it allows investigating the performance of multi-conjugated wavefront sensing using real time information from SCIDAR data and proving validity of the near field assumption. From preliminary Shack-Hartmann measurements we conclude that the instrument should be flexible to change optical layout and detection parameters according to the turbulence conditions. Therefore, the phase sensor branch includes automatically controlled moveable devices, and in the future, fast communication facilities between control computers of both SCIDAR and wavefront sensing are previewed. In this paper, we will present our objectives of building such an instrument, give a detailed state of art design, and considerate the preparation of first observational campaigns, that are the first scientific tasks to do.

Date Published: 11 November 2004
PDF: 11 pages
Proc. SPIE 5572, Optics in Atmospheric Propagation and Adaptive Systems VII, (11 November 2004); doi: 10.1117/12.565555

Published in SPIE Proceedings Vol. 5572:
Optics in Atmospheric Propagation and Adaptive Systems VII
John D. Gonglewski; Karin Stein, Editor(s)