Measurement of Atmospheric Noise

Abstract

Two methods of measuring atmospheric noise levels, subjective and objective, have been describe. The various technical aspects underlying the instrumentation for carrying out the measurements these methods have been critically examined and the results of the experiments, used as basis subjective measurements, have been described. A statistical correlation between the two methods measurements has been established. The values of minimum signal strength required for satisfactory' listening of broadcast programmes obtained by the subjective method followed at Delhi have be presented for the period from November 1955 to March 1958. The diurnal, seasonal and frequency variations of these values in the form of graphs have also been given. The absolute values of noise for different months, frequencies and times of the day have been given separately in the Appendix.