Download or read book Auroral Oval Plotter and Nomograph for Determining Corrected Geomagnetic Local Time Latitude and Longitude for High Latitudes in the Northern Hemisphere written by James A. Whalen and published by . This book was released on 1970 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: A nomographic computer is presented which graphically converts geographical coordinates and universal time into geomagnetic coordinates and geomagnetic local time in the Corrected Geomagnetic system of Hultqvist. The computer is formulated as a map of high latitudes in the Northern Hemisphere on which the position of the auroral oval can be projected directly for any time of day, for any magnetic activity, with account being taken of seasonal variation of the geomagnetic local time coordinate. Instructions for its use, discussion of its accuracy, and examples of its application are given. (Author).
Download or read book Auroral Oval Plotter and Nomograph for Determining Corrected Geomagnetic Local Time Latitude and Longitude for High Latitudes in the Northern Hemisphere written by James A. Whalen and published by . This book was released on 1970 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A nomographic computer is presented which graphically converts geographical coordinates and universal time into geomagnetic coordinates and geomagnetic local time in the Corrected Geomagnetic system of Hultqvist. The computer is formulated as a map of high latitudes in the Northern Hemisphere on which the position of the auroral oval can be projected directly for any time of day, for any magnetic activity, with account being taken of seasonal variation of the geomagnetic local time coordinate. Instructions for its use, discussion of its accuracy, and examples of its application are given. (Author)
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1971 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Environmental Research Papers written by and published by . This book was released on 1970 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Study of the Equatorward Edge of the Auroral Oval from Satellite Observations written by B. S. Dandekar and published by . This book was released on 1979 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: The auroral ovals in the northern and southern hemispheres observed by the optical instruments aboard the DMSP satellites are studied on a statistical basis in terms of the temporal, spatial, and magnetic activity dependence of the equatorward edge of the diffuse (continuous) aurora. In the nightside (18-08 CGT), the equatorward edges of the auroral ovals are located predominantly in the latitude range 61 deg - 69 deg CGL. They show strong dependence on the levels of magnetic activity. Of the indices Kp, AE, Dst, and Q, the Q index is correlated best with the position of the equatorward edge of the diffuse aurora. Assuming that the auroral oval is approximately circular in a CG coordinate system, the dependence of the radius of the auroral oval on magnetic activity is determined. The radius and the center of the auroral circle changes with variation in magnetic activity. The ovals of the northern and southern hemispheres consistently show an asymmetry. On the nightside, the oval in the southern hemisphere is located about 1 deg closer to the equator than the oval in the northern hemisphere.
Download or read book Meteorological and Geoastrophysical Abstracts written by and published by . This book was released on 1975 with total page 572 pages. Available in PDF, EPUB and Kindle. Book excerpt: Covering the world's literature on meteorology, climatology, atmospheric chemistry and physics, physical oceanography, hydrology, glaciology, and related environmental sciences.
Download or read book The Effect of the Ionosphere on Communication Navigation and Surveillance Systems written by John M. Goodman and published by . This book was released on 1988 with total page 716 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Satellite Density Measurements with the Rotatable Calibration Accelerometer ROCA written by Frank A. Marcos and published by . This book was released on 1979 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: Satellite accelerometer measurements of atmospheric density have provided significant improvement in our understanding of the structure and dynamics of the lower thermosphere. Derivation of accurate data with this technique requires removal of instrument bias from the total sensor output. The ROCA (Rotatable Calibration Accelerometer) experiment was flown to provide and orbital calibration capability on the three-axis stabilized S3-4 satellite. The ROCA sensitive axis could be operated in either of two orientations selectable by ground command. For density measurement (normal operating mode) the sensitive axis was aligned with the satellite velocity vector. For direct measurement of bias, the sensitive axis was aligned perpendicular to the velocity vector. Utilization of the inflight calibration technique showed a dependence of the bias upon the instrument operating temperature. Removal of the bias-temperature component from the total acceleration signal obtained in the normal operating mode permits derivation of accurate density data. Measurements of atmospheric density were obtained during approximately 600 orbits over a five month period. The resulting ROCA data will be utilized for improved satellite ephemeris computations and for detailed studies of the lower thermosphere, particularly those related to energy inputs at high latitudes. (Author).
Download or read book Handbook of Geophysics and Space Environments written by U.S. Air Force Geophysics Laboratory and published by . This book was released on 1985 with total page 1066 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book 250 MHz GHz Scintillation Parameters in the Equatorial Polar and Auroral Environments written by Santimay Basu and published by . This book was released on 1986 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Journal of Geomagnetism and Geoelectricity written by and published by . This book was released on 1992 with total page 614 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ionospheric Scintillations TEC and In situ Density Measurements at an Auroral Location in the European Sector written by Eileen MacKenzie and published by . This book was released on 1987 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Geophysical Journal of the Royal Astronomical Society written by and published by . This book was released on 1977 with total page 816 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vols. 11 and 13 includes the Proceedings of the 2nd, 3rd, International Symposium on Geophysical Theory and Computers, Rehovoth, Israel, etc., 1965-66.
Download or read book Propagation Effects on Military Systems in the High Latitude Region written by H. Soicher and published by . This book was released on 1985 with total page 622 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Radio Science written by and published by . This book was released on 1988 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Ionosphere written by L. F. McNamara and published by . This book was released on 1991 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt: This introductory text describes the ionosphere and its effects on systems which use it, giving special emphasis to HF communications. Further sections cover topics such as the single station location of HF transmitters and over-the-horizon radar.
Download or read book Phase and Amplitude Scintillation Statistics at 244 MHz from Goose Bay Using a Geostationary Satellite written by Sunanda Basu and published by . This book was released on 1982 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
