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Measurement and modeling of land mobile satellite propagation at UHF and L-bandA propagation experiment is described in which a stratospheric balloon served as a transmitter platform at 870 and 1502 MHz in simulation of a land mobile satellite. A vehicle followed the drifting balloon along roads of western Texas and New Mexico, collecting at L-band amplitude and phase, and at UHF amplitude information only for elevation angles between 25 and 45 deg. The data obtained have been analyzed and are presented along with results from modeling of multipath scattering and roadside tree attenuation. The signal, with variations caused by multipath propagation and tree shadowing, was reduced by 3 dB at L-band and 2 dB at UHF for one percent of all locations. A median ratio of 3.9 was found between peak-to-peak phase (degrees) and power (dB) fluctuations. The ratio between L-band and UHF dB attenuation averages varied from 1.3 to 1.0 at fade levels from 6 to 23 dB. Optical sky brightness was measured and used to predict fade distribution with great accuracy. A single-scatterer multipath model is introduced. It is used to duplicate some of the measured data and to show the dependence of power variations on satellite elevation angle. Using Fresnel diffraction theory, the attenuation caused by a model tree was calculated to be near 10 dB and the maximum fade was found to increase by the logarithm of the number of branches.
Document ID
19880060196
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Vogel, Wolfhard J.
(Texas, University Austin, United States)
Hong, Ui-Seok
(Kwangwoon University Seoul, Republic of Korea, United States)
Date Acquired
August 13, 2013
Publication Date
May 1, 1988
Publication Information
Publication: IEEE Transactions on Antennas and Propagation
Volume: 36
ISSN: 0018-926X
Subject Category
Communications And Radar
Accession Number
88A47423
Funding Number(s)
CONTRACT_GRANT: JPL-956520
Distribution Limits
Public
Copyright
Other

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