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851.
Guidance law of a homing missile is implemented using an extended high gain observer without the model assumptions on target maneuvers. First, for a class of multi-input–multi-output nonlinear systems, extended high-gain observers are used for output feedback control with partial practical stabilization. Then the method is applied to the guidance law implementation of a homing missile with bearing only measurement. Simulation results show satisfactory performance. 相似文献
852.
V. I. Bogdanov 《Russian Aeronautics (Iz VUZ)》2018,61(2):244-251
The new conceptual design of simple gas turbine engines for different purposes is presented. A choked-flow low-pressure turbine is used that allows reducing the number of stages and gas temperature in the relative motion ahead of blades. Application of such turbines with uncooled blades to reduce the cost of power-limited engines is considered. 相似文献
853.
854.
The multicriteria optimization problem on joint choice of a carrier aircraft and main design parameters of an air launcher
decoy are considered. The estimation of the design parameter values for the aerial decoy is based on the statistical data
processing with the use of the methods for constructing nonlinear regression. The result of solving this problem is a set
of Pareto-optimal geometry characteristics of the carrier aircraft and aerial decoy. A person who is responsible for decision-making
should choose the most reasonable variant from these characteristics. An example of solving the problem is presented. 相似文献
855.
856.
Space Science Reviews - 相似文献
857.
858.
O.W. Lennartsson H.L. Collin W.K. Peterson E.G. Shelley 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2000,25(12):2417-2420
Ion composition data from the first 22 months of operation of the Polar/TIMAS instrument, covering the 15-eV/e to 33-keV/e energy range, have been surveyed to determine the typical abundance, at solar minimum, of N2+, NO+ and O2+ ions in the auroral ion outflow, as compared to that of the better known O+ ions. The results indicate that molecular ions have roughly the same energy distribution as the O+ ions, with maximum differential flux occurring below 400 eV, but are far less abundant, by two orders of magnitude. The molecular ions also differ from the O+ ions in that they seem more specifically associated with enhanced geomagnetic activity. 相似文献
859.
K.K. Singh J. Singh M. Altaf Ashutosh K. Singh S. Kumar A.K. Singh Shyampati Lalmani 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2010
The purpose of this paper is to describe some unusual whistlers (doublets and triplets) and VLF hiss emission recorded simultaneously on February 18, 1998 during nighttime at a low latitude Indian ground station Jammu (geomag. lat., 22° 26′ N; L = 1.17), and to make some discussions about their origin. The detailed structures of the observed VLF hiss emission clearly show that these emissions confined to a narrow continuous frequency band. Some times the frequency of hiss band oscillates and subsequently touches the upper edge of the first whistler component of the doublet. Detailed structures of the dynamic spectra of whistler and VLF hiss emission are briefly presented. From the dispersion analysis of the whistler doublets and triplets, it is found that the individual whistlers of the doublets and triplets simultaneously observed on the same day are one-hop whistlers having propagation path along higher and closely spaced L-values. Our result also shows that VLF hiss has been generated in the equatorial region of higher L-values. Generation and propagation mechanisms are briefly discussed. 相似文献
860.
K. Gustafsson L. Sihver D. Mancusi T. Sato G. Reitz T. Berger 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2010
The radiation environment in space is very different from the one encountered on Earth. In addition to the sparsely ionizing radiation, there are particles of different Z with energies ranging from keV up to hundreds of GeV which can cause severe damage to both electronics and humans. It is therefore important to understand the interactions of these highly ionizing particles with different materials such as the hull of space vehicles, human organs and electronics. We have used the Particle and Heavy-Ion Transport code System (PHITS), which is a three-dimensional Monte Carlo code able to calculate interactions and transport of particles and heavy ions with energies up to 100 GeV/nucleon in most matter. PHITS is developed and maintained by a collaboration between RIST (Research Organization for Information Science & Technology), JAEA (Japan Atomic Energy Agency), KEK (High Energy Accelerator Research Organization), Japan and Chalmers University of Technology, Sweden. For the purpose of examining the applicability of PHITS to the shielding design we have simulated the ESA facility Matroshka (MTR) designed and lead by the German Aerospace Center (DLR). Preliminary results are presented and discussed in this paper. 相似文献