Accession Number : ADA255518
Title : Long-Term Averages of Globally-Measured ELF/VLF Radio Noise
Descriptive Note : Technical rept.
Corporate Author : STANFORD UNIV CA SPACE TELECOMMUNICATIONS AND RADIOSCIENCE LAB (STAR)
Personal Author(s) : Bowen, M M ; Fraser-Smith, A C ; McGill, P R
Report Date : Mar 1992
Pagination or Media Count : 57
Abstract : In this report we present the results of a statistical study of a year of data obtained as part of the STAR Laboratory's global survey of ELF/VLF radio noise (frequencies in the range 10 Hz to 32 kHz). The data included in the study were obtained from seven measurement instruments (radiometers) located at both high and low latitudes. Average amplitude and voltage deviation (d) statistics from each of the six stations were first divided into four three- month seasons and then averaged at every measurement frequency to give two separate sets of long-term averages. Long-term averages show characteristic trends in the measurements due to the manner in which noise propagates in the earth-ionosphere waveguide. The average amplitudes of the measurements decrease with frequency, reaching a minimum around 1 kHz, and rise again towards 10 kHz. The voltage deviation amplitudes generally rise with frequency except for a depression of values around 1 kHz.
Descriptors : *NOISE(RADIO) , *RADIO INTERFERENCE , SEASONAL VARIATIONS , RADIOMETERS , AMPLITUDE , DIURNAL VARIATIONS , VERY LOW FREQUENCY , EXTREMELY LOW FREQUENCY
Subject Categories : Radiofrequency Wave Propagation
Distribution Statement : APPROVED FOR PUBLIC RELEASE