Using a multi-point Continuous Doppler sounding system we investigate propagation directions and velocities of Gravity Waves (GWs) in the ionosphere at altitudes from ~150 km to ~250 km. The velocities and directions are computed from the time delays between the observations of corresponding GWs at different reflection points that correspond to various sounding paths. We focused on the GWs that produce an S-shaped trace in Doppler shift spectrograms since it is know that these patterns are formed if the disturbances (waves) mainly propagate in the horizontal plane. The S-shaped signatures also make it possible to estimate the errors of measurements. The system that we used was developed in the Institute of Atmospheric Physics, Czech Republic and has been operated in the western part of the Czech Republic. A similar system was also installed in the Western Cape, South Africa at the end of May 2010. A statistical study shows that the analyzed GWs propagate with typical horizontal velocities from ~100 to ~200 m/s. The north-south component of GW velocities depends on the season and/or daytime. The analyzed waves propagated northward from April to August. At the same time, the north-south component of neutral winds calculated by the HWM07 model had an opposite sign.