The experimental study of laser beam propagation in turbulence is relevant to fields such as adaptive optics and optical communications. Turbulence sensing for astronomical purposes requires a convergent laser beam adequately focused on the sodium mesospheric layer. Free Optical communications ground-to-satellite usually are based on divergent laser beams travelling partially through the atmosphere. We present several measurements of the gaussian beam radius for divergent and convergent laser beams propagated in vertical paths. The determinations were carried out at the Teide Observatory (Canary Islands) from the analysis of Rayleigh scattering. The turbulence profile was simultaneously measured with a SCIntillation Detection And Ranging (SCIDAR) instrument. This way, we analyse the influence of the different turbulence layers in the focusing problem through the empirical relation between the beam waist radius and the intensity of the turbulence. We present the experimental set-up, the first results of the experiment and the plans to conduct a statistical study in the future.