DocumentCode :
985956
Title :
Propagation of the Low-Frequency Radio Signal
Author :
Johler, J. Ralph
Author_Institution :
National Bureau of Standards, Boulder, Colo.
Volume :
50
Issue :
4
fYear :
1962
fDate :
4/1/1962 12:00:00 AM
Firstpage :
404
Lastpage :
427
Abstract :
The propagation of a radio signal and the propagation in the time domain is reviewed for linear amplitude systems. The particular case of the propagation of a ground wave pulse is considered in detail. A stretching in the form or shape of the pulse is noted as a result of the filtering action of the propagation medium. Theoretical transfer characteristics for the media of propagation of LF signals are introduced and methods of computation are considered. The particular case of a signal transmitted between two points on the earth´s surface is considered from the viewpoint of propagation in the time domain. The field of LF waves propagated around the earth is, in large measure, influenced by the reflection and transmission processes at the ionosphere. Such processes are evaluated theoretically with the aid of Maxwell´s equations together with an equation which describes the electron motion in the presence of a static magnetic field, a superposed electrodynamic field together with mechanical collisions between electrons and ions, such as the Langevin equation of motion of the electron. The use of full mathematical rigor in the application of these equations is feasible and indeed desirable at LF. Thus, the application of these equations to an electron-ion model plasma with arbitrary orientation of the superposed magnetic induction results in anisotropic transmission and reflection properties. The full rigor can be applied to model plasmas in which the electron density and collision frequency vary with altitude.
Keywords :
Earth; Electrons; Magnetic field measurement; Maxwell equations; Plasma applications; Plasma density; Plasma properties; Pulse shaping methods; Reflection; Shape;
fLanguage :
English
Journal_Title :
Proceedings of the IRE
Publisher :
ieee
ISSN :
0096-8390
Type :
jour
DOI :
10.1109/JRPROC.1962.288037
Filename :
4066658
Link To Document :
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