Studies of the atmospheric dispersion over complex terrain, with the aid of smoke plumes, enable the direct observation of the marginal density probability of the emitted particles. Experiments near the ground correlate the turbulence easurements at 10 m height and plume pictures (profile, elevation and plan) taken by a network of cine-cameras. Experiments in altitude correlate the turbulence profile, measured by a microaerological equipment and the development of five smoke plumes of different colors, distributed every 25 m along the cable of a tethered balloon. The graphical data treatment and video editing of the films enable easy access to the results. These measurements will be used to check the validity of different assumptions proposed in the stochastic modelings (Gaussian or non Gaussian) of atmospheric dispersion.