Ionospheric Constraints on VHF/UHF Communications Links during Solar Maximum and Minimum Periods
An extensive VHF/UHF scintillation data base covering the frequency range of VHF to a few gigahertz has been utilized to determine the magnitudes of phase and intensity scintillations and their temporal/spatial structures during the sunspot maximum and minimum periods. The equatorial portion of the...
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ftdtic:ADA201770 2023-05-15T16:30:10+02:00 Ionospheric Constraints on VHF/UHF Communications Links during Solar Maximum and Minimum Periods Basu, Santimay MacKenzie, E. Basa, Sunanda EMMANUEL COLL BOSTON MA 1988-06 text/html http://www.dtic.mil/docs/citations/ADA201770 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA201770 en eng http://www.dtic.mil/docs/citations/ADA201770 Approved for public release; distribution is unlimited. DTIC AND NTIS Astrophysics Atmospheric Physics Plasma Physics and Magnetohydrodynamics Radiofrequency Wave Propagation *IONIZATION *COMMUNICATIONS NETWORKS *SCINTILLATION *SUNSPOTS *F REGION *AURORAE REPRINTS DENSITY MEASUREMENT POSITION(LOCATION) INTENSITY ARTIFICIAL SATELLITES POLAR CAP SOLAR CYCLE ULTRAHIGH FREQUENCY VERY HIGH FREQUENCY SYNCHRONOUS SATELLITES GREENLAND GEOMAGNETISM EQUATORIAL REGIONS ANOMALIES STATIONS ASCENSION ISLAND FREQUENCY CONTROL PE62101F WUAFGL46430903 Text 1988 ftdtic 2016-02-23T07:35:40Z An extensive VHF/UHF scintillation data base covering the frequency range of VHF to a few gigahertz has been utilized to determine the magnitudes of phase and intensity scintillations and their temporal/spatial structures during the sunspot maximum and minimum periods. The equatorial portion of the study has been based on geostationary satellite observations at Huancayo, a station on the magnetic equator, and at Ascension Island, which is an equatorial anomaly station having an extremely disturbed irregularity environment. The high- latitude part of the study is based on quasi-stationary satellite measurements at a polar cap location (Thule) and two auroral locations (Goose Bay and Tromso) . The Tromso observations are augmented with the Defense Nuclear Agency HiLatsatellite beacon measurements during the solar minimum period. The data indicate a strong solar cycle control of scintillation activity at all locations, resulting in a drastic reduction of the magnitudes and occurrence of scintillations during the current solar minimum period. This pattern is consistent with both a reduction of F region ionization density and a reduction of irregularity generation in the solar minimum period. At the magnetic equator the magnitude of scintillations at 1.5 GHz seldom exceeds 3 dB with the percentage occurrence > 2 dB varying from 70% during high sunspot conditions to 30% during low sunspot conditions. At the crest of the equatorial anomaly, on the other hand, during the solar maximum in 1979, fades of 20 dB at 1.5 GHz are observed 30% of the time. Reprints. Pub. in Radio Science, v23 n3 p363-378 May-Jun 1988. Text Greenland Thule Tromso Tromso Defense Technical Information Center: DTIC Technical Reports database Greenland Tromso ENVELOPE(16.546,16.546,68.801,68.801) |
institution |
Open Polar |
collection |
Defense Technical Information Center: DTIC Technical Reports database |
op_collection_id |
ftdtic |
language |
English |
topic |
Astrophysics Atmospheric Physics Plasma Physics and Magnetohydrodynamics Radiofrequency Wave Propagation *IONIZATION *COMMUNICATIONS NETWORKS *SCINTILLATION *SUNSPOTS *F REGION *AURORAE REPRINTS DENSITY MEASUREMENT POSITION(LOCATION) INTENSITY ARTIFICIAL SATELLITES POLAR CAP SOLAR CYCLE ULTRAHIGH FREQUENCY VERY HIGH FREQUENCY SYNCHRONOUS SATELLITES GREENLAND GEOMAGNETISM EQUATORIAL REGIONS ANOMALIES STATIONS ASCENSION ISLAND FREQUENCY CONTROL PE62101F WUAFGL46430903 |
spellingShingle |
Astrophysics Atmospheric Physics Plasma Physics and Magnetohydrodynamics Radiofrequency Wave Propagation *IONIZATION *COMMUNICATIONS NETWORKS *SCINTILLATION *SUNSPOTS *F REGION *AURORAE REPRINTS DENSITY MEASUREMENT POSITION(LOCATION) INTENSITY ARTIFICIAL SATELLITES POLAR CAP SOLAR CYCLE ULTRAHIGH FREQUENCY VERY HIGH FREQUENCY SYNCHRONOUS SATELLITES GREENLAND GEOMAGNETISM EQUATORIAL REGIONS ANOMALIES STATIONS ASCENSION ISLAND FREQUENCY CONTROL PE62101F WUAFGL46430903 Basu, Santimay MacKenzie, E. Basa, Sunanda Ionospheric Constraints on VHF/UHF Communications Links during Solar Maximum and Minimum Periods |
topic_facet |
Astrophysics Atmospheric Physics Plasma Physics and Magnetohydrodynamics Radiofrequency Wave Propagation *IONIZATION *COMMUNICATIONS NETWORKS *SCINTILLATION *SUNSPOTS *F REGION *AURORAE REPRINTS DENSITY MEASUREMENT POSITION(LOCATION) INTENSITY ARTIFICIAL SATELLITES POLAR CAP SOLAR CYCLE ULTRAHIGH FREQUENCY VERY HIGH FREQUENCY SYNCHRONOUS SATELLITES GREENLAND GEOMAGNETISM EQUATORIAL REGIONS ANOMALIES STATIONS ASCENSION ISLAND FREQUENCY CONTROL PE62101F WUAFGL46430903 |
description |
An extensive VHF/UHF scintillation data base covering the frequency range of VHF to a few gigahertz has been utilized to determine the magnitudes of phase and intensity scintillations and their temporal/spatial structures during the sunspot maximum and minimum periods. The equatorial portion of the study has been based on geostationary satellite observations at Huancayo, a station on the magnetic equator, and at Ascension Island, which is an equatorial anomaly station having an extremely disturbed irregularity environment. The high- latitude part of the study is based on quasi-stationary satellite measurements at a polar cap location (Thule) and two auroral locations (Goose Bay and Tromso) . The Tromso observations are augmented with the Defense Nuclear Agency HiLatsatellite beacon measurements during the solar minimum period. The data indicate a strong solar cycle control of scintillation activity at all locations, resulting in a drastic reduction of the magnitudes and occurrence of scintillations during the current solar minimum period. This pattern is consistent with both a reduction of F region ionization density and a reduction of irregularity generation in the solar minimum period. At the magnetic equator the magnitude of scintillations at 1.5 GHz seldom exceeds 3 dB with the percentage occurrence > 2 dB varying from 70% during high sunspot conditions to 30% during low sunspot conditions. At the crest of the equatorial anomaly, on the other hand, during the solar maximum in 1979, fades of 20 dB at 1.5 GHz are observed 30% of the time. Reprints. Pub. in Radio Science, v23 n3 p363-378 May-Jun 1988. |
author2 |
EMMANUEL COLL BOSTON MA |
format |
Text |
author |
Basu, Santimay MacKenzie, E. Basa, Sunanda |
author_facet |
Basu, Santimay MacKenzie, E. Basa, Sunanda |
author_sort |
Basu, Santimay |
title |
Ionospheric Constraints on VHF/UHF Communications Links during Solar Maximum and Minimum Periods |
title_short |
Ionospheric Constraints on VHF/UHF Communications Links during Solar Maximum and Minimum Periods |
title_full |
Ionospheric Constraints on VHF/UHF Communications Links during Solar Maximum and Minimum Periods |
title_fullStr |
Ionospheric Constraints on VHF/UHF Communications Links during Solar Maximum and Minimum Periods |
title_full_unstemmed |
Ionospheric Constraints on VHF/UHF Communications Links during Solar Maximum and Minimum Periods |
title_sort |
ionospheric constraints on vhf/uhf communications links during solar maximum and minimum periods |
publishDate |
1988 |
url |
http://www.dtic.mil/docs/citations/ADA201770 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA201770 |
long_lat |
ENVELOPE(16.546,16.546,68.801,68.801) |
geographic |
Greenland Tromso |
geographic_facet |
Greenland Tromso |
genre |
Greenland Thule Tromso Tromso |
genre_facet |
Greenland Thule Tromso Tromso |
op_source |
DTIC AND NTIS |
op_relation |
http://www.dtic.mil/docs/citations/ADA201770 |
op_rights |
Approved for public release; distribution is unlimited. |
_version_ |
1766019894122381312 |