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Ionospheric electron density irregularities observed by satellite‐to‐satellite, dual‐frequency, low‐low doppler tracking link
Author(s) -
Estes Robert D.,
Grossi Mario D.
Publication year - 1984
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/rs019i004p01098
Subject(s) - doppler effect , earth's magnetic field , satellite , ionosphere , electron density , geology , geodesy , physics , terminator (solar) , local time , tec , remote sensing , geophysics , electron , astronomy , magnetic field , quantum mechanics , statistics , mathematics
A low‐low, satellite‐to‐satellite, dual‐frequency, Doppler tracking experiment was performed by the Harvard‐Smithsonian Center for Astrophysics on the occasion of the 1975 Apollo‐Soyuz Test Project. The data are analyzed here for irregularities in electron density at the altitude of 212 km. The differential Doppler data with the relative motion term removed are integrated to obtain a representation of the electron density variation along the satellite path. Well‐known large‐scale features such as the equatorial geomagnetic anomaly and day/night ionization level differences are clearly observed in the integrated data. The larger crest of the morning geomagnetic anomaly is seen to occur in the southern (winter) hemisphere in agreement with previous observations. In addition, a sharp peak in the electron density at the day‐to‐night transition point is observed in two consecutive revolutions. This effect may be due to the previously postulated atmospheric shock wave generated by supersonic motion of the terminator.