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Multisite Observations of the VLF Transequatorial Propagation Anomaly
Author(s) -
Lynn K. J. W.
Publication year - 1969
Publication title -
radio science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.371
H-Index - 84
eISSN - 1944-799X
pISSN - 0048-6604
DOI - 10.1029/rs004i003p00203
Subject(s) - middle latitudes , equator , sunrise , anomaly (physics) , amplitude , geology , latitude , geophysics , magnetic dip , earth's magnetic field , atmospheric sciences , ionosphere , geodesy , physics , magnetic field , optics , condensed matter physics , quantum mechanics
Phase and amplitude records of 18.6‐kHz transmissions from NPG/NLK received at eight sites varying in distance from 4,360 to 13,420 km southwest of the transmitter, confirm the existence of a region within ±20° of the magnetic equator, in which VLF propagation parameters vary significantly from their midlatitude values. At all seven sites that involved transequatorial propagation paths, anomalies (including cycle slipping) were observed during the sunrise transition. The nature and temporal occurrence of these anomalies depended on the distance of the receiver from the magnetic equator. The experimentally derived dependence on magnetic latitude of the mode conversion ratio of the two least attenuated propagating modes and their apparent interference spacing are presented.