In short, one can say that SCIDAR is a method to measure (among others) the vertical profile of atmospheric optical turbulence. The method is based on an analysis of spatio-temporal correlations of stellar scintillation images. In astronomy, SCIDAR is more and more used to characterize astronomical sites on a regular base. In particular adaptive optics instruments may benefit from real-time SCIDAR data, e.g. knowing the iso-planatic angle and windspeed may help to optimize AO observations.

A nice and compact introduction to SCIDAR can be found here.

An excellent and detailed description of SCIDAR in the context of multi-conjugated adaptive optics can be found here.

MPIA and Steward Observatory have built a SCIDAR facility for the Large Binocular Telescope (LBT) on Mount Graham, Arizona. While Steward Observatory was engaged in the optical and opto-mechanical design of the instrument, MPIA was responsible to deliver the real-time data reduction system.

An overview of the hard- and software architecture is shown here.

Status of the project as of September 2001 is here; March 2001 can be found here. Since about 2002 (see this conference paper) the system is fully operational.

Links:

Remy Avila's homepage http://www.astrosmo.unam.mx/~r.avila

Publications:

LBT facility SCIDAR: recent results
McKenna, Daniel L.; Avila, Remy; Hill, John M.; Hippler, Stefan; Salinari, Piero; Stanton, Paul C.; Weiss, Robert, SPIE 4839, pp. 825-836 (2003)
(pdf file)

Simultaneous SCIDAR and Adaptive Optics Measurements: Results and Applications
A.R. Weiß, S. Hippler, M.E. Kasper, M. Feldt, SPIE 4538, pp. 135-143 (2002).
(pdf file)

Simultaneous Measurements of the Fried Parameter r0 and the Isoplanatic Angle theta₀ Using SCIDAR and Adaptive Optics - First Results
A.R. Weiß, S. Hippler, M.E. Kasper, N.J. Wooder, J.C. Quartel, Astronomical Site Evaluation in the Visible and Radio Range. ASP Conference Proceedings, Vol. 266. Edited by J. Vernin, Z. Benkhaldoun, and C. Muñoz-Tuñón. ISBN: 1-58381-106-0. San Francisco, Astronomical Society of the Pacific, 2002., p.86 (pdf file)