9512470)
Department of Defense, Washington, DC
DOD
Sponsoring Organization:
(United States)
Conference Title: TENERP conference
Conference Location: Monterey, CA (United States)
Conference Date: 21-24
Jun 1993
\
Publication Date:
Report Number(s):
1993
(15 p)
LA-UR-93-2140
Order Number: DE93016615
Contract Number
(DOE):
W-7405-ENG-36
Document Type: Report; Conference Literature
Language: English
Journal Announcement: EDB9317
Availability: OSTI;
NTIS;
GPO Dep.
Distribution:
(Report):0
(MF):4
MN-000
Subfile:
ERA
(Energy
Research Abstracts);
Exchange);
NTS
‘
CONF -9306190--1
(NTIS).
IIA
US DOE Project/NonDOE Project: P
ETD
(DOE contractor)
.
(Energy Technology Data
Country of Origin: United States
Country of Publication: United States
Abstract: In August 1990, the authors set up an hf path on the equatorial
path between Maloelap Atoll and Bikini Atoll. This path, which had a
range of 702 km, reflected in the ionosphere approximately 100 km north
of the Altair radar location on Kwajalein. Transmitters at Maloelap
broadcasted four cw tones within bandwidth of either 4 kHz,
9 kHz,
or
70 kHz to be used to determine frequency coherence and also a
phase-coded pseudo random sequence with a bandwidth of 60 kHz (channel
probe) to be used to determine time delay spread. A spatial array of
antennas was deployed at Bikini to measure spatial and frequency
coherence using the cw broadcasts. The system was run in the
post-sunset time period over two weeks during which almost every night
showed significant degradation due to spread F resulting in rapid
fading, decreased spatial and frequency coherence, and increased time
delay spread. Doppler spreads of greater than 20 Hz were not uncommon,
and the spatial correlation distances and frequency coherence
bandwidths became so small (50 meters and 1 kHz respectively) that the
experiment had to be readjusted. Measurements taken by the Altair
incoherent scatter radar and the CUPRI 50 MHz coherent scatter radar
indicate that although the bistatic hf channel is affected by the large
scale plume structures, most of the
is done by the bottomside spread F.
[open quotes]damage[close quotes]
Major Descriptors: *IONOSPHERE -- SIGNAL DISTORTION; *RADIOWAVE RADIATION
~- SIGNAL DISTORTION; *RADIOWAVE RADIATION -- WAVE PROPAGATION
Descriptors: DOPPLER BROADENING; MHZ RANGE 01-100; SPREAD F
©
Broader Terms: EARTH ATMOSPHERE; ELECTROMAGNETIC RADIATION; F REGION;
FREQUENCY RANGE; IONOSPHERE; LINE BROADENING; MHZ RANGE; PLANETARY
IONOSPHERES; RADIATIONS
Subject Categories:
(1992-)
10/5/309
03532084
661300*
-- Other Aspects of Physical Scienc® --
(Item 9 from file: 103)
AIX-24-057509; EDB-93-104565
Title: Nations of the earth report
Publication Date:
1992
({[2 v.]
90036549
Corporate Source:
United Nations, New York, NY (USA) (Code: 6465050)
Conference Title: United Nations conference on environment and development:
earth summit
Conference Location: Rio de Janeiro (Brazil)
Conference Date: 1-12 Jun
1992
Publisher:
Geneva (Switzerland)
UNCED
p)
Report Number(s) :
CONF -9206148-ISBN: 92-1-100483-7 92-1-100484-5
Document Type: Book;
Language: English
Conference Literature
Journal Announcement: EDB9317
Subfile:
ETD
(Energy Technology Data Exchange).
INIS
(non-US Atomindex