Phase And Amplitude Scintillation Statistics At 244 Mhz From Goose Bay Using A Geostationary Satellite

Author : Sunanda Basu
Publisher : Unknown
Page : 68 pages
File Size : 51,9 Mb
Release : 1982
Category : Artificial satellites
ISBN : UOM:39015095143015

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Phase and Amplitude Scintillation Statistics at 244 MHz from Goose Bay Using a Geostationary Satellite by Sunanda Basu Pdf

Phase and amplitude scintillation measurements made at 244 MHz from Goose Bay using the geostationary satellite Fleetsat are presented. An extended dynamic range receiver with an extremely stable local oscillator measured the phase variations with the precision of a coherent system subject to certain limitations. The data were obtained for a 10-month period in 1979 during a high sunspot epoch to extend the limited temporal coverage of the orbiting Wideband satellite data. The report presents scintillation statistics in the manner required for communications system planning. The nighttime phase scintillations showed maximum occurrence during the spring and increased greatly in relation to the amplitude scintillations during times of significant magnetic activity. The increase of phase scintillations in relation to amplitude scintillations was attributed to an enhanced ionospheric drift during times of magnetic disturbances. The phase spectral index of the Fleetsat data was found to be larger than that determined from Wideband data. To further our understanding of auroral irregularity generation mechanisms, this report also presents a case study of energetic particle precipitation spectra, the topside thermal density response of such precipitation and the coordinated phase and amplitude perturbation spectra created by such an energy input into the ionosphere.

Author : Jules Aarons
Publisher : Unknown
Page : 252 pages
File Size : 48,8 Mb
Release : 1984
Category : Ionosphere
ISBN : UOM:39015095140482

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Ionospheric Radio Wave Propagation by Jules Aarons Pdf

Author : Anonim
Publisher : Unknown
Page : 764 pages
File Size : 51,9 Mb
Release : 1983
Category : Aeronautics
ISBN : UIUC:30112104409427

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Scientific and Technical Aerospace Reports by Anonim Pdf

Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.

Author : G. J. Bishop
Publisher : Unknown
Page : 144 pages
File Size : 43,7 Mb
Release : 1987
Category : Artificial satellites
ISBN : UOM:39015095140771

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An Advanced System for Measurement of Transionospheric Radio Propagation Effects Using GPS Signals by G. J. Bishop Pdf

An advanced system for measurement of transionospheric radio propagation effects was developed, utilizing the TI-4100 four-channel Global Positioning System (GPS) receiver. During AFGL's Polar ARCS campaign at Sondrestrom, Greenland in February-March 1987, the system successfully measured ionospheric total electron content (TEC), phase scintillation, and amplitude scintillation on both GPS carrier frequencies, from up to four satellites simultaneously. This was the first time it has been possible to measure these parameters simultaneously, in multiple directions, in the high-latitude regions. Coupled with the simultaneous optical and incoherent scatter radar diagnostics obtained during the Polar ARCS campaign, these measurements significantly improve our capability to characterize high latitude ionospheric structures, particularly their temporal and spatial variation. Additionally, the development of this advanced system has contributed significantly to the technology base for specification of the Transionospheric Sensing System (TISS) for the Air Weather Service. The system can also be software upgraded to perform special navigation in addition to ionospheric measurements in airborne applications.

Author : Eileen MacKenzie
Publisher : Unknown
Page : 52 pages
File Size : 42,5 Mb
Release : 1987
Category : Auroras
ISBN : UOM:39015095140839

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Ionospheric Scintillations/TEC and In-situ Density Measurements at an Auroral Location in the European Sector by Eileen MacKenzie Pdf

The orbiting HiLat satellite launched in 1983 offered an opportunity for studying ionospheric scintillation parameters in relation to in-situ measurements of ionization density, drift velocity, field-aligned current, and particle precipitation during the sunspot minimum period. This report discusses results of a morphological study based on observations of scintillations and total electron content (TEC) at the auroral oval station at Tromso, Norway, during the period Dec 1983 - Oct 1985. The geometrical enhancement of scintillations observed during alignment of the propagation with the local magnetic L-shell is shown to be the most consistent and conspicuous feature of scintillations in the nighttime auroral oval. The dynamics of the spatial and temporal extent of this region are illustrated in the invariant latitude/magnetic local time grid. Steepening of phase spectral slope in the geometrical enhancement region is indicative of the presence of L-shell aligned sheet-like irregularities at long scale lengths. The seasonal variation of TEC determined from the differential Doppler measurements of HiLat transmissions is discussed in relation to the in-situ density measurements at 830 km. The results are also used to illustrate the dependence of ionospheric structure parameters on short-term variability of solar activity during the sunspot minimum period. This study provides an insight into the nature of magnetospheric coupling with the ionosphere at high latitudes.

Author : Sunanda Basu
Publisher : Unknown
Page : 136 pages
File Size : 41,9 Mb
Release : 1981
Category : Auroras
ISBN : UOM:39015095141779

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Comparison of Ionospheric Scintillation Statistics from the North Atlantic and Alaskan Sectors of the Auroral Oval Using the Wideband Satellite by Sunanda Basu Pdf

Aerosol models have been developed for the lower atmosphere. These models are representative of conditions found in rural, urban, and maritime air masses. The changes in the aerosol properties with variations in the relative humidity are discussed. To describe the aerosol optical properties in the extreme of 100 percent relative humidity, several fog models are presented. For each model the coefficients for extinction, scattering, and absorption, the angular scattering distribution, and other optical parameters have been computed for wavelengths between 0.2 and 40 microns. These aerosol models are presented together with a review of their experimental basis. The optical properties of these models are discussed and some comparisons of the model with experimental measurements are presented.

Author : U.S. Air Force Geophysics Laboratory
Publisher : Unknown
Page : 1066 pages
File Size : 45,9 Mb
Release : 1985
Category : Geophysics
ISBN : UCSD:31822002400885

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Handbook of Geophysics and Space Environments by U.S. Air Force Geophysics Laboratory Pdf

Author : Anonim
Publisher : Unknown
Page : 338 pages
File Size : 45,7 Mb
Release : 1981
Category : Environmental geology
ISBN : CHI:62485523

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Environmental Research Papers by Anonim Pdf

Author : Anonim
Publisher : Unknown
Page : 914 pages
File Size : 53,9 Mb
Release : 1985
Category : Atmospheric chemistry
ISBN : UOM:39015034725583

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Meteorological and Geoastrophysical Abstracts by Anonim Pdf

Author : Anonim
Publisher : Unknown
Page : 504 pages
File Size : 45,8 Mb
Release : 1988
Category : Radio meteorology
ISBN : MINN:31951000613382A

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Radio Science by Anonim Pdf

Author : Santimay Basu
Publisher : Unknown
Page : 40 pages
File Size : 50,7 Mb
Release : 1986
Category : Ionosphere
ISBN : UOM:39015095141126

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250 MHz/GHz Scintillation Parameters in the Equatorial, Polar and Auroral Environments by Santimay Basu Pdf

Ionospheric scintillation effects encountered in the equatorial anomaly crest, polar cap and auroral regions have been contrasted to provide information for the design and evaluation of the performance of satellite communication links in ghese regions. The equatorial anomaly region is identified as the most disturbed irregularity environment where the amplitude and phase structures of VHF/L-band scintillations are primarily dictated by the strength of scattering rather than ionospheric motion. In the anomaly region, the spectra of intense amplitude scintillations at VHF and L-band are characterized by uniform power spectral density from the lowest frequency (10 MHz) to 4 Hz at VHF and to 1 Hz at L-band and steep rolloff at higher fluctuation frequencies with power law indices of -5 to 07. Such structures are compatible with intensity decorrelation times of 0.1 and 0.3 sec at VHF and L-band frequencies, respectively. The phase spectra are described by power law variation of psd with frequency with typical spectral indices of -2. 4. The strong scattering at VHF induces extreme phase rates of 200 deg. in 0.1 sec. The 90th percentile values of rms phase deviation at 250 MHz with 100-sec detrend are found to be 16 rads in the early evening hours whereas amplitude scintillation can cover the entire dynamic range of 30 dB not only at 250 MHz but at L-band as well.

Author : Anonim
Publisher : Unknown
Page : 556 pages
File Size : 41,9 Mb
Release : 1985
Category : Ionosphere
ISBN : UOM:39015028404799

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Effect of the Ionosphere on C3I Systems by Anonim Pdf

Author : North Atlantic Treaty Organization. Advisory Group for Aerospace Research and Development
Publisher : Unknown
Page : 234 pages
File Size : 42,6 Mb
Release : 199?
Category : Aeronautics
ISBN : UFL:31262081531583

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AGARD Lecture Series by North Atlantic Treaty Organization. Advisory Group for Aerospace Research and Development Pdf

Author : Anonim
Publisher : Unknown
Page : 1654 pages
File Size : 45,8 Mb
Release : 1983
Category : Research
ISBN : UOM:39015034740038

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Government Reports Annual Index by Anonim Pdf

Sections 1-2. Keyword Index.--Section 3. Personal author index.--Section 4. Corporate author index.-- Section 5. Contract/grant number index, NTIS order/report number index 1-E.--Section 6. NTIS order/report number index F-Z.

Author : U.S. Air Force Geophysics Laboratory
Publisher : Unknown
Page : 1052 pages
File Size : 41,8 Mb
Release : 1985
Category : Geophysics
ISBN : MINN:31951000759466F

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Handbook of Geophysics and the Space Environment by U.S. Air Force Geophysics Laboratory Pdf