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Fade measurements at L-band and UHF in mountainous terrain for land mobile satellite systemsFading results related to land mobile satellite communications at L-band (1502 MHz) and UHF (870 MHz) are described. These results were derived from an experiment performed in a series of canyon passes in the Boulder, Colorado region of the US. The experimental configuration involved a helicopter as the source platform, which maintained a relatively fixed geometry with a mobile van containing the receiver and data-acquisition system. An unobstructed line of sight between the radiating sources and the receiving van was, for the most part, also maintained. In this configuration, the dominant mechanism causing signal fading (or enhancement) is a result of multipath. The resulting fade distributions demonstrated that at the 1 percent and 5 percent levels, 5.5- and 2.6-dB fades were on the average exceeded at L-band and 4.8- and 2.4-dB at UHF, respectively, for a path elevation angle of 45 deg. The canyon results as compared with previous roadside-tree-shadowing results demonstrate that the deciding factor dictating fade margin for future land mobile satellite systems is tree shadowing rather than fades caused by multipath.
Document ID
19880046272
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Vogel, Wolfhard J.
(Texas, University Austin, United States)
Goldhirsh, Julius
(Johns Hopkins University Laurel, MD, United States)
Date Acquired
August 13, 2013
Publication Date
January 1, 1988
Publication Information
Publication: IEEE Transactions on Antennas and Propagation
Volume: 36
ISSN: 0018-926X
Subject Category
Communications And Radar
Accession Number
88A33499
Funding Number(s)
CONTRACT_GRANT: N00039-87-C-5301
CONTRACT_GRANT: JPL-956520
Distribution Limits
Public
Copyright
Other

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