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Title: Field-aligned electron density irregularities near 500 km Equator to polar cap topside sounder observations

Abstract

In addition to spread F, evidence for field-aligned electron density irregularities is commonly observed on Alouette 2 topside sounder ionograms recorded near perigee (500 km). This evidence is provided by distinctive signal returns from sounder-generated Z mode waves. At low latitudes these waves become guided in wave ducts caused by field-aligned electron density irregularities and give rise to strong long-duration echoes. At high latitudes, extending well into the polar cap, these Z mode waves (and stimulated electrostatic waves at the plasma frequency) produce a series of vertical bars on the ionogram display as the satellite traverses discrete field-aligned density structures. The radio frequency (RF) noise environment to be expected in the 400 to 500 km altitude region from low to high latitudes was examined by analyzing perigee Alouette 2 topside sounder data. All observed noise bands were scaled on nearly 200 topside sounder ionograms recorded near perigee at low, mid, and high latitude telemetry stations. The minimum and maximum frequencies of each noise band were entered into a data base or computer analysis. The signals of primary interest in the perigee study were found to be sounder-generated. 15 references.

Authors:
Publication Date:
Research Org.:
Goddard Space Flight Center, Greenbelt, MD
OSTI Identifier:
6162933
Resource Type:
Journal Article
Journal Name:
Radio Sci.; (United States)
Additional Journal Information:
Journal Volume: 20
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; IONOSPHERE; ELECTRON DENSITY; AURORAE; PLASMA; PLASMA WAVES; RADIOWAVE RADIATION; SPACE SHUTTLES; AIRCRAFT; EARTH ATMOSPHERE; ELECTROMAGNETIC RADIATION; PLANETARY IONOSPHERES; RADIATIONS; SPACE VEHICLES; VEHICLES; 640201* - Atmospheric Physics- Auroral, Ionospheric, & Magetospheric Phenomena

Citation Formats

Benson, R F. Field-aligned electron density irregularities near 500 km Equator to polar cap topside sounder observations. United States: N. p., 1985. Web. doi:10.1029/RS020i003p00477.
Benson, R F. Field-aligned electron density irregularities near 500 km Equator to polar cap topside sounder observations. United States. doi:10.1029/RS020i003p00477.
Benson, R F. Sat . "Field-aligned electron density irregularities near 500 km Equator to polar cap topside sounder observations". United States. doi:10.1029/RS020i003p00477.
@article{osti_6162933,
title = {Field-aligned electron density irregularities near 500 km Equator to polar cap topside sounder observations},
author = {Benson, R F},
abstractNote = {In addition to spread F, evidence for field-aligned electron density irregularities is commonly observed on Alouette 2 topside sounder ionograms recorded near perigee (500 km). This evidence is provided by distinctive signal returns from sounder-generated Z mode waves. At low latitudes these waves become guided in wave ducts caused by field-aligned electron density irregularities and give rise to strong long-duration echoes. At high latitudes, extending well into the polar cap, these Z mode waves (and stimulated electrostatic waves at the plasma frequency) produce a series of vertical bars on the ionogram display as the satellite traverses discrete field-aligned density structures. The radio frequency (RF) noise environment to be expected in the 400 to 500 km altitude region from low to high latitudes was examined by analyzing perigee Alouette 2 topside sounder data. All observed noise bands were scaled on nearly 200 topside sounder ionograms recorded near perigee at low, mid, and high latitude telemetry stations. The minimum and maximum frequencies of each noise band were entered into a data base or computer analysis. The signals of primary interest in the perigee study were found to be sounder-generated. 15 references.},
doi = {10.1029/RS020i003p00477},
journal = {Radio Sci.; (United States)},
number = ,
volume = 20,
place = {United States},
year = {1985},
month = {6}
}