Characteristics of atmospheric radio noise observed at Singapore

Measurements of the amplitude probability distributions of atmospheric radio noise in a power bandwidth of approximately 400c/s, made at the Radio Research Station, Singapore, from September 1958 to July 1960, are presented for frequencies of 24 kc/s, 145 kc/s, 11 Mc/s and 20 Mc/s. Results are normalised to the r.m.s. amplitude to show the diurnal and seasonal variations of noise structure. The temporal variations in parameters derived from the distributions are also illustrated and the results explained by reference to the prevailing meteorological and ionospheric conditions. Parameters relating to noise amplitude are the mean power and the average value of the noise-envelope voltage; those relating to noise structure are the ratio of the r.m.s. to the average value and the dynamic range. The programme of measurements was similar to that made at the Radio Research Station in England during the International Geophysical Year. Wherever possible, the Singapore data are compared with the corresponding results for England.