We investigate emission and propagation of auroral kilometric radiation in the auroral zones of the Earth, using the geometrics optics approximation in order to describe the ray trajectory and the transfer equation to obtain the intensity of the wave along the trajectory. Both the cyclotron emissivity and the components of the dielectric tensor are evaluated by using the locally homogeneous plasma approximation, taking into account thermal effects and considering both the energetic and the background electron populations. The amplification level predicted by the transfer equation is similar to the value obtained from simple integration of the amplification coefficient along the wave trajectory. Using model profiles which incorporate repeated series of density depletions inside large-scale auroral cavities, we show that these depletions may contribute to increase the wave amplification, as compared with the case of auroral cavities without internal structure. ¿ American Geophysical Union 1996