The SCIDAR built at the Applied Optics group of the Blackett
Laboratory of Imperial Colledge, London, was brought to La Silla by
Chris Walker and David Lara-Saucedo on July 7, 2002. It was installed
at the ESO 1m telescope, specially re-furbished for this mission by
the La Silla ESO staff. Miska Le Louarn (ESO) and Andrei Tokovinin
(CTIO) participated in this first SCIDAR run (July 7-13). Some data in
common with MASS was obtained on July 10, but with only 5.3-s segments
of SCIDAR data processed as yet. The relative normalization was
adjusted and the SCIDAR profiles were convolved with MASS response for
the sake of comparison. In the graph below: full line - MASS, dashed
line - SCIDAR.
The second series of measurements was done in the period July 20-28 by Marc Sarazin, Ol'ga Vozyakova, Andrei Tokovinin and Jorge Araya. Marc has modified SCIDAR data processing. Still, SCIDAR shows too low Cn2 integrals, problems with normalization remain. The picture below shows the average of 20 SCIDAR blocks (8 minutes) measured on July 25, 2002 (dash) with the corresponding MASS average profile (full line). SCIDAR profiles were relatively stable within this block, so the erors of the mean were computed and displayed as horizontal bars. The unstable character of turbulence on this night can be seen from the MASS data (the period of comparison with Run155 is shown by rectangle).
The SCIDAR individual profiles for Run155 are plotted in this figure to show their stability and the actual SCIDAR vertical resolution. Each profile is obtained from 5.3 seconds of data. Vertical axis - in 1e-13 m^{1/3}.
Restoration of SCIDAR profiles is illustrated by the figures for
Run 155_0 (sucessful restoration) and
Run 165_0 (failed restoration).
