Atmospheric Noise Interference to Broadcasting in the 5 Mc./S. Band at Poona

Abstract

The paper gives a report of the measurement of atmospheric noise interference to broadcasting in the S Mc./s. band at Poona (18·31°N 73·55°E.), during the hours 18.00 to 23.00 (I.S.T.) by the method described by Aiya. The results are utilized to compute the data on noise necessary for broadcast services. These data are compared with the estimates of CRPL, Washington, and the measurements carried out on behalf of the Radio Research Board, London, at places in or near India. The discrepancies are explained and it is shown that both give lower values of noise. Noise levels are estimated from lightning discharge data and compared with measured values. There is close agreement between the estimates and the measured values. In all these comparisons, it is shown that such of the differences, as arise between the 3 Mc./s. measurements reported elsewhere and the 5 Mc./s. measurements, arise entirely from the differences in the propagation characteristics at the two frequencies.