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11.
A new approach to the problem of direction and distance finding of magnetospheric ULF oscillations is described. It is based on additional information about the structure of geoelectromagnetic field at the Earths surface which is contained in the known relations of the theory of magnetovariation and magnetotelluric sounding. This allows us to widen the range of diagnostic tools by using observations of Alfvén oscillations in the PC 3–5 frequency band and the ion-cyclotron waves in the PC 1 frequency band. Preliminary results of the remote sensing of the magnetosphere at low-latitudes using the MHD ranger technique are presented. The prospects for remote sensing of the plasmapause position are discussed. 相似文献
12.
TOPEX/POSEIDON is a joint American/French ocean topography experiment. It was launched by an Ariane launch vehicle on August 10, 1992 to study and map ocean circulation. The primary functions of the navigation subsystem of the TOPEX/POSEIDON project are to establish and maintain a pre-designed reference orbit, and to measure, monitor, and predict the satellite ground track continuously. To fulfill these functions, trajectory analysis is required to design and generate all trajectory related products. This paper is concerned with the trajectory functions of TOPEX/POSEIDON navigation. It describes various activities of this support function. 相似文献
13.
The ionospheric Alfvén resonator (IAR) control mechanism over the EMIC wave transmission to the ground is demonstrated on a selected long-term frequency-variable subauroral Pcl event. The proper ionospheric plasma data obtained from EISCAT were accessible in a wide altitude range. Applying the numerical method of simulation of a realistic inhomogeneous IAR, the problem of appearance and disappearance of the ground Pc1 signal record was clarified on the basis of coincidence between the EMIC wave frequency spectrum and the IAR fundamental frequency peak (the frequency window). A shift of the signal source field line to lower latitudes during the development of the disturbance was noticed, and the signal frequency variation on the ground was modelled in the nonstationary IAR. Variation of the IAR altitude structure in the fundamental frequency was illustrated on altitude profiles of the normalized wave magnetic field amplitude in the horizontal and vertical components. Particular conditions of L
- and R
-wave mode incidence were assumed. The electron density vertical profile of IAR determines the effective resonator dimensions. In this way the IAR fundamental frequency window controls the signal within the ionosphere and on the ground. 相似文献