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931.
932.
A.S. Biryukov O.R. Grigoryan S.N. Kuznetsov A.V. Sinyakov E.D. Tolstaya 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1998,21(12):1665-1668
New experimental data obtained on the orbital station ‘MIR’ in 1991 during solar maximum are discussed. Electron fluxes with Ee>75 keV were registered for three different directions as well as for electrons with Ee>300 and 600 keV. Spatial and time distributions of electron fluxes in the trapping region are presented. In the inner radiation belt an additional maximum is observed at L=1.25–1.35, and the fluxes in the 22-05h MLT interval are 2–3 orders of magnitude smaller, than during other local times. In this region a flattening of the electron spectrum is observed. The results obtained were compared with the AE-8 model. 相似文献
933.
The Solar Terrestrial Relations Observatory (STEREO) is primarily a solar and interplanetary research mission, with one of the natural applications being in the area of space weather. The obvious potential for space weather applications is so great that NOAA has worked to incorporate the real-time data into their forecast center as much as possible. A subset of the STEREO data will be continuously downlinked in a real-time broadcast mode, called the Space Weather Beacon. Within the research community there has been considerable interest in conducting space weather related research with STEREO. Some of this research is geared towards making an immediate impact while other work is still very much in the research domain. There are many areas where STEREO might contribute and we cannot predict where all the successes will come. Here we discuss how STEREO will contribute to space weather and many of the specific research projects proposed to address STEREO space weather issues. The data which will be telemetered down in the Space Weather Beacon is also summarized here. Some of the lessons learned from integrating other NASA missions into the forecast center are presented. We also discuss some specific uses of the STEREO data in the NOAA Space Environment Center. 相似文献
934.
Montgomery J.B. Sanderson R.B. Baxley F.O. 《Aerospace and Electronic Systems Magazine, IEEE》1998,13(4):29-35
The use of high speed multicolor imaging sensors provides a valuable tool for characterizing both the infrared signatures of missiles as well as clutter. Over 14 flight hours worth of collections were made of difficult to characterize clutter. This additional data can be utilized to develop and improve missile warning algorithms for better false alarm rates. These analyses show that although a two color staring system could have multiple advantages over a single color system in false alarm rejection, the clutter rejection capabilities can be limited by the relatively low inter-band correlations between the red and blue bands 相似文献
935.
V. Angelopoulos D. Sibeck C. W. Carlson J. P. McFadden D. Larson R. P. Lin J. W. Bonnell F. S. Mozer R. Ergun C. Cully K. H. Glassmeier U. Auster A. Roux O. LeContel S. Frey T. Phan S. Mende H. Frey E. Donovan C. T. Russell R. Strangeway J. Liu I. Mann J. Rae J. Raeder X. Li W. Liu H. J. Singer V. A. Sergeev S. Apatenkov G. Parks M. Fillingim J. Sigwarth 《Space Science Reviews》2008,141(1-4):453-476
THEMIS was launched on February 17, 2007 to determine the trigger and large-scale evolution of substorms. During the first seven months of the mission the five satellites coasted near their injection orbit to avoid differential precession in anticipation of orbit placement, which started in September 2007 and led to a commencement of the baseline mission in December 2007. During the coast phase the probes were put into a string-of-pearls configuration at 100 s of km to 2 RE along-track separations, which provided a unique view of the magnetosphere and enabled an unprecedented dataset in anticipation of the first tail season. In this paper we describe the first THEMIS substorm observations, captured during instrument commissioning on March 23, 2007. THEMIS measured the rapid expansion of the plasma sheet at a speed that is commensurate with the simultaneous expansion of the auroras on the ground. These are the first unequivocal observations of the rapid westward expansion process in space and on the ground. Aided by the remote sensing technique at energetic particle boundaries and combined with ancillary measurements and MHD simulations, they allow determination and mapping of space currents. These measurements show the power of the THEMIS instrumentation in the tail and the radiation belts. We also present THEMIS Flux Transfer Events (FTE) observations at the magnetopause, which demonstrate the importance of multi-point observations there and the quality of the THEMIS instrumentation in that region of space. 相似文献
936.
M.I. Tyasto O.A. Danilova L.I. Dorman V.M. Dvornikov V.E. Sdobnov 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2008,42(9):1556-1563
We report on a study of cosmic ray cutoff rigidity variations during the strong geomagnetic storm of 18–24 November 2003. We employed the most recent Tsyganenko magnetospheric model to represent the very strong disturbed Magnetosphere. We used this magnetic field for the cosmic ray trajectory calculations to determine the geomagnetic cutoff rigidity throughout this period of severe geomagnetic disturbance. We determine the cutoff rigidity changes during this period by two methods, by trajectory calculations and by the spectrographic global survey method. The values of the change of cutoff rigidities obtained by two different methods are correlated with the Dst and interplanetary magnetic field and plasma parameters and result in correlation coefficients in the range 0.63–0.84 for the various cosmic ray stations. The result of this study indicates that the most significant contributions to the cutoff rigidity changes are due to Dst variation although the influence of solar wind density and Bz and By components of IMF variations is significant. 相似文献
937.
O.S. Oyekola Akin Ojo 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2008,41(9):1500-1509
The variability of the F2-layer even during magnetically quiet times are fairly complex owing to the effects of plasma transport. The vertical E × B drift velocities (estimated from simplified electron density continuity equation) were used to investigate the seasonal effects of the vertical ion drifts on the bottomside daytime ionospheric parameters over an equatorial latitude in West Africa, Ibadan, Nigeria (Geographic: 7.4°N, 3.9°E, dip angle: 6°S) using 1 year of ionsonde data during International Geophysical Year (IGY) of 1958, that correspond to a period of high solar activity for quiet conditions. The variation patterns between the changes of the vertical ion drifts and the ionospheric F2-layer parameters, especially; foF2 and hmF2 are seen remarkable. On the other hand, we observed strong anti-correlation between vertical drift velocities and h′F in all the seasons. We found no clear trend between NmF2 and hmF2 variations. The yearly average value of upward daytime drift at 300 km altitude was a little less than the generally reported magnitude of 20 ms−1 for equatorial F-region in published literature, and the largest upward velocity was roughly 32 ms−1. Our results indicate that vertical plasma drifts; ionospheric F2-layer peak height, and the critical frequency of F2-layer appear to be somewhat interconnected. 相似文献
938.
N. Hasebe N. Yamashita O. Okudaira S. Kobayashi H. Yamamoto T. Ishizaki K. Hirano K. Sakurai T. Miyachi M. Miyajima M. Fujii M.-N. Kobayashi T. Takashima E. Shibamura O. Gasnault S. Maurice C. d’Uston R. Reedy M. Grande 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2008
The high precision gamma-ray spectrometer (GRS) is scheduled to be launched on the lunar polar orbiter of the SELENE mission in 2007. The GRS consists of a large Ge crystal as a main detector and massive bismuth germanate crystals as an anticoincidence detector. A Stirling cryocooler was adopted in cooling the Ge detector. The flight model of SELENE GRS has been completed and an energy resolution of 3.0 keV (FWHM) at 1.332 MeV has been achieved. The spectrometer aims to observe nuclear line gamma rays emitted from the lunar surface in a wide energy range from 100 keV to 12 MeV for one year and more to obtain chemical composition on the entire lunar surface. The gamma-ray data enable us to study lunar geoscience problems including crust and mantle composition, and volatile reservoirs at polar regions. 相似文献
939.
Y.O. Migoya Orué S.M. Radicella P. Coïsson R.G. Ezquer B. Nava 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2008
TEC values obtained from TOPEX satellite were compared with the International Reference Ionosphere (IRI) 2001 model estimates. The present work also shows results of the IRI model with the option of a new topside electron density distribution (NeQuick model). TOPEX TEC measurements, which include years of high and middle to low solar activity (2000 and 2004), were analyzed by binning the region covered by the satellite (±66°) every five degrees of modip. In general, there is good agreement between IRI predictions and Topex measurements. Cases with large disagreements are observed at low and high latitudes during high solar activity. Comparing the model predictions using the default IRI2001 model and the NeQuick topside option show that the default IRI 2001 version represents the observed data in a more realistic way, but appears to be less reliable at high and low latitudes in some cases. 相似文献
940.
Yu. V. Lissakov S. I. Klimov O. V. Lapshinova N. M. Pushkin A. S. Mashkov 《Cosmic Research》2007,45(3):253-256
The quasi-stationary electrical fields have been measured in the near-surface zone of the Kvant module of the Mir orbital complex using vibration-type sensors of the Zond-Zaryad instrument. The analysis of measurements has shown that, depending on the spacecraft’s surface section shape (an octagon), four areas of the electrical fields configuration (and of the plasma component density) were revealed in the spacecraft vicinity: a ram with angular extension of about 120° (±60°), two side areas with angular extension of about 60° each, and a wake with angular extension of about 120° (±60°). The electrical field in the ram has a small absolute value. In the side areas, the electrical field can have either a negative or positive value, and it is smaller in magnitude than that in the ram. The electrical field in the wake has a three-petal structure (and an even more complicated structure is also possible): the negative value of the field (with angular extension of about 45°), the positive value of the field (with angular extension of about 30°), and, again, the negative value of the field (with angular extension of about 45°). Absolute value of the field in the wake is at least an order of magnitude higher than that in the ram and on the side surfaces. 相似文献