  A wind tunnel experiment is shown to examine the reproducibility of generated
wind fields in the laboratory utilizing an active grid. A motion protocol of
the grid, designed to mimic a measured atmospheric wind speed time series, is
therefore repeated 50 times and the flow is measured by a 2D hotwire (x-wire)
system. The acquired wind speed time series are analysed in two different ways
to identify the reproducible time scales. A direct comparison using the cross
covariance function combined with two filtering methods and a statistic
approach using one and two point analysis. Like that the reproducible time and
length scales could be linked to the active grid motion and design. The
identification of the reproducible time scales of a turbulent signal generated
by means of an active grid is suitable to improve the possible wind fields in
laboratory experiments.
