Ozone monitoring in the troposphere and lower stratosphere has been performed on an operational basis by using a ground-based lidar station set up in 1980 at the Haute Provence Observatory (France). A description of the experimental system is given with a special emphasis on the technical achievements that take into account the optimization criteria of the differential absorption laser technique used in the measurements. The results obtained during several experiments in 1980--1981 are discussed in terms of ozone variability in the troposphere and lower straphosphere, ozone exchanges between these two altitude regions, and tropospheric ozone budget.