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Geocoronal imaging with Dynamics Explorer - A first lookThe ultraviolet photometer of the University of Iowa spin-scan auroral imaging instrumentation on board Dynamics Explorer-1 has returned numerous hydrogen Lyman alpha images of the geocorona from altitudes of 570 km to 23,300 km (1.09 R sub E to 4.66 R sub E geocentric radial distance). The hydrogen density gradient is shown by a plot of the zenith intensities throughout this range, which decrease to near celestial background values as the spacecraft approaches apogee. Characterizing the upper geocorona as optically thin (single-scattering), the zenith intensity is converted directly to vertical column density. This approximation loses its validity deeper in the geocorona, where the hydrogen is demonstrated to be optically thick in that there is no Lyman alpha limb brightening. Further study of the geocoronal hydrogen distribution will require computer modeling of the radiative transfer. Previously announced in STAR as N83-20889
Document ID
19830059898
Document Type
Reprint (Version printed in journal)
Authors
Rairden, R. L. (Iowa Univ. Iowa City, IA, United States)
Frank, L. A. (Iowa Univ. Iowa City, IA, United States)
Craven, J. D. (Iowa, University Iowa City, IA, United States)
Date Acquired
August 11, 2013
Publication Date
July 1, 1983
Publication Information
Publication: Geophysical Research Letters
Volume: 10
ISSN: 0094-8276
Subject Category
GEOPHYSICS
Report/Patent Number
AD-A132344
Funding Number(s)
CONTRACT_GRANT: NGL-16-001-002
CONTRACT_GRANT: N00014-76-C-0016
CONTRACT_GRANT: NAS5-24293
Distribution Limits
Public
Copyright
Other