In a refracting atmosphere the sound waves are changing their direction and velocity due to the effective sound speed gradient. By using a sound propagation model based on geometric acoustic the excess attenuation of sound levels generated by refraction in a moving stratified atmosphere and reflections at the ground were estimated for a lot of atmospheric states. The input data for the model are vertical profiles of wind vector and temperature from measurements and boundary layer models. To validate the numerically estimated data a measuring campaign was carried out in autumn 2004, where two measurement systems were applied. The method of acoustic tomography supplied travel times and relative amplitudes of the sound signals propagating on distances between 75 and 500 meters for calculating the excess attenuation. On the other side there was an additional system for monitoring sound pressure levels directly. The correlation between measurements and simulations was compared for sound propagation in downwind and upwind direction. The particularity of the measuring period was a very stably layered atmosphere. This stratification caused a strong refraction of the sound rays downward to the ground. Because of multiple reflections on the surface the excess attenuation generates an increasing sound level in compare to sound propagation in a non-refracting atmosphere.