An atmospherics analyzer

The enormously powerful radiation from lightning discharges has been used as a tool for the study of the ionosphere at very low frequencies. Previous workers have calculated the height of the ionosphere and the distance to the radiation source by application of the ray theory of multiple ionospheric reflections. Time measurements for use in the height and distance formulas were obtained by direct measurement of recorded oscillograms. Time resolution was limited and the calculations were extremely tedious. This paper describes a complete system which records the received atmospheric wave form and simultaneously derives a plot of the time intervals between peaks of the wave form vs time. The time-interval plot greatly facilitates data reduction by means of a simple curve-fitting technique. Accuracy of measurement of height and distance is limited chiefly by the validity of the multiple reflection theory and the assumption of a simple layer structure in the ionosphere. The time differences are measured more accurately than is ordinarily possible with direct measurement on the waveform. The system automatically derives frequency-time plots for whistling atmospherics and relates the whistler to preceding impulsive atmospherics. Consumption of photographic film is low. The system can be used to visually monitor tape-recorded atmospherics.