An analytical model for the description of the electromagnetic waves propagation in a layered medium consisting of sectors having the locally spherical symmetric distributions of refractivity is introduced. Model presents analytical expressions for the phase path and refractive attenuation of electromagnetic waves. Influuence of the inclined ionospheric layers is a cause of the ionospheric interference in the trans-ionospheric communication satellite-to-satellite or satellite-to-Earth links. It follows from the analytical model that the identification of the inclined ionospheric layers contributions and measurements of their location and parameters may be fulfilled by use of comparative analysis of the amplitude variations and the eikonal accelerationof the RO signals. Model is applied to analysis of the radio occultation (RO) signals propagating through the ionosphere and atmosphere. Model explains existence of the ionospheric contributions in the RO signals at the altitudes 30-90km of the RO ray perigee as connected with influence of a tangent point in the ionosphere where the electron density gradient is perpendicular to the RO ray trajectory. By use of the CHAMP RO amplitude data a description of di®erent types of the ionospheric contributions to the RO signals is introduced and compared with results of measurements obtained earlier in the communication link satellite-to-Earth at frequency 1.5415 GHz of MARSAT satellite.