  The paper presents the results of an ambient vibration monitoring campaign
conducted on so-called Clock Tower (Torre delle Ore), one the best known and
most visited monuments in the historic centre of Lucca. The vibrations of the
tower were continuously monitored from November 2017 to March 2018 using
high-sensitivity instrumentation. In particular, four seismic stations provided
by the Istituto Nazionale di Geofisica e Vulcanologia and two three-axial
accelerometers developed by AGI S.r.l., spin-off of the Istituto Nazionale di
Astrofisica, were installed on the tower. The measured vibration level was
generally very low, since the structure lies in the middle of a limited traffic
area. Nevertheless, the availability of two different types of highly sensitive
and accurate instruments allowed the authors to follow the dynamic behaviour of
the tower during the entire monitoring period and has moreover provided
cross-validation of the results.
