Atmospheric refractivity sounding is of great importance to the meteorological and military applications. An experiment
was conducted for sounding the atmospheric refractivity on the top of the Wuling Mountain in August, 2005. Profiles of
the atmospheric refractivity were obtained by both the mountain-based GPS and the tomographic method. Comparison
shows that there is a bias of -3.83N and a standard deviation of 7.03N between the mountain-based GPS and the
radiosonde. A bias less than 1% among different receivers proves that the receivers tested can meet the demand of the
radio occultation technique. A very good consistence among the profiles by the mountain-based GPS, the tomographic
method and the radiosonde suggests the effectiveness of both the mountain-based GPS and the tomographic method,
indicating the great potential in the future meteorological application.