[en] The homogeneous radial equation of atmospheric tides has been solved numerically, through its analogy with the Helmholtz equation, adopting a realistic temperature structure below 110 km. A linear law for the variable coefficient is assumed and the relationships between exact solutions of the equation and the WKB approximations are therefore illustrated. The analysis has been carried out for two types of wave propagation: the oscillatory and the trapped modes of the diurnal and semidiurnal oscillations. (author)