The Relation between Atmospheric Disturbances and Wave Length in Radio Reception

L.W. Austin
1921 Proceedings of the IRE  
The fact that the atmospheric disturbances, commonly called "static" or "strays" by American operators, increase with the wave length to which the receiving system is tuned has been known qualitatively for a number of years. The object of the present experiments is to gain some degree of quantitative information on the subject. Neglecting the lightninig clicks and hissing disturbances which for the most part produce little interference with communication, we have in general to deal with the
more » ... o deal with the rumbling or grinding static which probably originates somewhere in the upper atmosphere, and which may perhaps be compared in its method of propagation to radio signals sent out from an airplane. Regardless of the orientation of the original oscillating body, the wave front spreads out in a more or less spherical form. When the wave strikes the earth the lines of force become grounded and travel off over the surface as tho transmitted from an antenna situated at some point roughly below the center of disturbance. Observations which will be described in another place, show that the wave front at 50 ft. (15 m.) from the ground is approximately vertical like that from a distaint sending station. Of course there will be somie disturbance centers nearly overhead, but these generally form only an insignificant portion of the whole. It has frequently been thought that static is entirely aperiodic, and that it produces a pure shock effect on the antenna. This seems somewhat doubtful, since none of the aperiodic types of artificial static produced in the laboratory, even of the most violent kind, have ever been anywhere nearly so difficult to eliminate as the natural disturbances. It seems more probable that it consists of a great number of distinct disturbances coming *
doi:10.1109/jrproc.1921.220094 fatcat:23c7tdpsufcqbp7i42s6aooveq