An approach to tropospheric duct propagation

A modal solution for the em propagation in a spherical stratified troposphere is derived, via the Marcuvitz-Schwinger formalism. The approximations due to the small curvature of the earth are illustrated. The representation of the sources via the complete set of modal solutions is presented, as well as the excitation factors, computed for the vertical electric or magnetic dipole. The possible use of digital and analog computers is highlighted. Future plans for the work are the computations of a great deal of digital and analog solutions, and also the study of the influence of the random variability of the tropospheric refraction index. In the Appendix, a preliminary case [f(z)=az] is presented.