Surface and degenerate waves in radio-wave propagation problems

The role of the surface and degenerate waves in classical radio wave propag ation problems above the plane and spherical Earth and in the ionosphere-Ea rth waveguide channel is analyzed. It is shown that these waves can signifi cantly affect the total electromagnetic field. The origin of the strong eff ect that the surface waves can exert on the field above open structures cau sing the interference field pattern is considered. Transequatorial propagat ion of very low-frequency radio waves in the irregular anisotropic spherica l surface waveguide at night governed by the effect of normal mode degenera tion is studied.