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