RESULTS OF THE FIELD INTENSITY MEASUREMENT HF RADIO WAVES AT NIGHT ON BOARD THE "SOYA"

Abstract

This paper describes the result of the , field intensity measurement of HF waves which was carried out at night on the way from Tokyo to Cape Town on board the "SOYA". Field intensities measured were lower than those of the so-called "unabsorbed field intensity" and the lower the frequency, the more rapidly the field intensity decreases with the distance of transmission. Hence, it is suggested that the non-deviative absorption must be taken into consideration. From the measurement on 2.5Mc/s wave, it was derived that the nondeviative absorption converted into the vertical incidence was equal to 1.0db. On the other hand, the weighted mean value for all frequencies measured was 2.5db. The difference between these values is examined herein