Lateral electromagnetic waves along plane boundaries - A summarizing approach

Lateral electromagnetic waves along a plane boundary between homogeneous half-spaces are reviewed. The electromagnetic fields generated by vertical and horizontal electric dipoles near the boundary between air and the earth are summarized in terms of a new unified theory of lateral-wave propagation. Complete theoretically determined fields are displayed and compared with measured fields at f = 600 MHz relative to the boundary between air and salt water. Near, intermediate, and asymptotic fields are related graphically to the new general theory and to the approximate and restricted formulas of Norton and Banos as well as to the Zenneck wave. Application is made to the problem of communication with submerged submarines by means of transmitters consisting of electrically short monopoles in air and horizontal traveling-wave antennas and directional arrays in sea water. The properties of the antennas are evaluated in the frequency range between 10 and 30 kHz and at f = 1 kHz. The effects of reflections from the ionosphere and of the earth's curvature are not included.