Short-term magnetic field alignment variations of equatorial ionospheric irregularities

Journal Article · Wed Jun 01 04:00:00 EDT 1988 · Radio Sci.; (United States)

DOI:https://doi.org/10.1029/RS023i003p00331· OSTI ID:6832146

Johnson, A L

The ionospheric irregularities that cause equatorial scintillation are elongated along the north-south magnetic field lines. During a 1981 field campaign at Ascension Island, 250-MHz receivers were spaced from 300 m to 1.6 km along the field lines, and the signals received from the Marisat satellite were cross correlated. Data collected during eight nights of fading showed a linear relationship between fading rate and cross correlation. The alignment of the antennas was adjusted to give a zero time lag between the widely spaced receivers with a measurement accuracy of 0.03 s. Since the average irregularity velocity was 125 m/s, this time accuracy translated to an angular measurement accuracy of 0.1 deg. During a 4-hour period of nightly fading, occasional differences in time of arrival were noted that corresponded to a tilt in the north-south alignment of + or - 1 deg. Data from several nights of fading were analyzed, and each night exhibited the same variance in the north-south irregularity alignment. It is postulated that the shift in the measured peak correlation may have been caused by patches of irregularities at different altitudes where the magnetic field lines have a slightly different direction. 13 references.

• Research Organization: USAF, Avionics Laboratory, Wright-Patterson AFB, OH (USA)
• OSTI ID: 6832146
• Journal Information: Radio Sci.; (United States), Journal Name: Radio Sci.; (United States) Vol. 23; ISSN RASCA
• Country of Publication: United States
• Language: English

Related Subjects

640201* -- Atmospheric Physics-- Auroral
Ionospheric
& Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
DISTURBANCES
EARTH ATMOSPHERE
GEOMAGNETIC FIELD
IONOSPHERE
MAGNETIC FIELD CONFIGURATIONS
MAGNETIC FIELDS
PLANETARY IONOSPHERES
VARIATIONS