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Statistical analysis of VLF radio emissions triggered by power line harmonic radiation and observed by the low‐altitude satellite DEMETER
Author(s) -
Parrot Michel,
Nĕmec František,
Santolík Ondřej
Publication year - 2014
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
eISSN - 2169-9402
pISSN - 2169-9380
DOI - 10.1002/2014ja020139
Subject(s) - ionosphere , magnetosphere , harmonics , daytime , satellite , harmonic , altitude (triangle) , physics , line (geometry) , atmospheric sciences , environmental science , radiation , very low frequency , geophysics , meteorology , magnetic field , voltage , acoustics , optics , astronomy , geometry , mathematics , quantum mechanics
DEMETER was a low‐altitude satellite in operation between 2004 and 2010 in a circular polar orbit. One of its main scientific objectives was to study ionospheric perturbations related to man‐made activity. This paper investigates electromagnetic emissions triggered by Power Line Harmonic Radiation (PLHR), the man‐made waves emitted at harmonics of 50 or 60 Hz. They look like rising tones or hooks with a starting frequency associated to a parent line with the frequency equal to a multiple of 50 or 60 Hz. They occur preferentially during daytime in a frequency band between 1 and 4 kHz. It is shown that these emissions are rather frequent at high latitudes (3 < L <6) above industrialized areas during periods of moderate magnetic activity. Their average intensity is of the order of 10 μV 2 m −2 Hz −1 . PLHR propagates in the magnetosphere and triggers emissions due to wave‐particle interactions in the equatorial region.