Abnormal Polarization of the Atmospheric Pulses reflected successively from the Ionosphere

Abstract

WHILE engaged in the determination of the direction of arrival of atmospherics by the conventional cathode-ray tube direction-finder, it was observed that, on occasions, for atmospherics of comparatively distant origin, there were elliptic patterns of gradually decreasing eccentricity and tilt-angle along with one or more linear responses, although when tested with the audio-frequency oscillations from a signal generator fed into the aerial system of the cathode-ray tube direction-finder, the fluorescent screen exhibited only the usual linear responses. It appears certain that these elliptic patterns are evidences of abnormal polarization of the atmospheric pulses reflected successively from the ionosphere, the linear responses being due to the direct (or ground-wave) atmospheric pulses. More than forty oscillograms showing the elliptic patterns and lines were recorded during the monsoon months of 1955. Usually the tilt-angle of the ellipses was found to decrease with the increasing order of ionospheric reflexion. A reversal in the direction of precession was noticed in few cases.