  The Generalised Differential Image Motion Monitor (GDIMM) was proposed a few
years ago as a new generation instrument for turbulence monitoring. It measures
integrated parameters of the optical turbulence, i.e the seeing, isoplanatic
angle, scintillation index, coherence time and wavefront coherence outer scale.
GDIMM is based on a fully automatic small telescope (28cm diameter), equipped
with a 3-holes mask at its entrance pupil. The instrument is installed at the
Calern observatory (France) and performs continuous night-time monitoring of
turbulence parameters. In this communication we present long-term and seasonnal
statistics obtained at Calern, and combine GDIMM data to provide quantities
such as the equivalent turbulence altitude and the effective wind speed.

Instrumentation and Methods for Astrophysics