The Propagation of ELF Waves

Download or read book The Propagation of ELF Waves written by Edward Clifton Field and published by . This book was released on 1969 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt: Theoretical analysis of the propagation of electromagnetic waves in the frequency range 30 Hz to 1000 Hz in the earth-ionosphere waveguide. Full wave methods incorporating the vertical inhomogeneity of the ionosphere are used. The model ionospheres, which correspond to both normal and disturbed (polar cap absorption - PCA) conditions, are chosen to illustrate the sensitivity of the propagation to various ionospheric properties. Attenuation constants and phase velocities pertinent to various models are calculated. In addition, detailed calculations of the height dependences of the electromagnetic fields and Joule heating are presented. Resulting conclusions are drawn as to which ionospheric properties and altitude regions most strongly influence the mode structure in the various cases. For example, it is concluded that ions always dominate ELF propagation under moderately disturbed (PCA) conditions, but under ambient conditions, ions are an important factor only for frequencies lower than a few hundred Hz. (Author).