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The operating characteristics of a ducted rocket in the Mars atmosphere
46th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit, 2010The Mars vehicle which can fly in the Mars atmosphere is necessary to do detailed surveys of the surface of Mars. This vehicle needs a propulsion engine which can work in the Mars atmosphere, mainly consisting of carbon dioxide. The ducted rocket is effective as propulsion engine, because it uses carbon dioxide as an oxidizer and combusts metal as fuel.
Masamichi Ushijima +3 more
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Design of an ocean atmospheric duct signal processor
2010 International Symposium on Intelligent Signal Processing and Communication Systems, 2010The atmospheric refractive section plane retrieved from radar sea clutter is of importance for the might enhancement of military naval radar. In this paper, an atmospheric duct signal processor with hardware of an intermediate-frequency board and a high-speed DSP board, besides the arithmetic of clutter suppression and sea clutter extraction, have been
null Li XueHua +3 more
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Background covariance of atmospheric duct properties based on ensembles
2015 USNC-URSI Radio Science Meeting (Joint with AP-S Symposium), 2015In Refractivity Data Fusion (RDF), the Cartesian representation of refractivity calculated from the Numerical Weather Prediction (NWP) output is mapped into a set of 2-dimensional diagnostic variables which are surfaces over the NWP domain. The diagnostic parameters (e.g. duct base height, duct strength, duct thickness, evaporation duct height) include
Neil D. Gordon +4 more
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Ducted propagation in the atmosphere, from audible sound to infrasound.
The Journal of the Acoustical Society of America, 2010Earth’s atmosphere supports complicated and highly variable winds and temperature gradients. Temperature inversions and wind jets provide ducts in which sound can propagate efficiently to great distances from the source. Due to the intrinsic variability of the atmospheric winds, these sound ducts are also quite variable, both temporally and spatially ...
Roger Waxler +6 more
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Simulated Climatology of Atmospheric Ducts Over the Persian Gulf
Boundary-Layer Meteorology, 2005A simulated climatology of ducts in the Persian Gulf area was produced with the MM3 atmospheric model. From November to January ducts were sporadic, land and surface based, shallow and weak. From February to October ducts of all types occurred. In the duct season, spatial and temporal variations were related to the land/sea distribution and to day and ...
M. Zhu, B. W. Atkinson
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Ducted Acoustic Gravity Waves in a Nearly Isothermal Atmosphere
The Journal of the Acoustical Society of America, 1967The propagation of acoustic gravity waves is analyzed in atmospheres that have vertical profiles of sound speed squared of the form c2(z) = c2(∞)±Δc2e−2/l, where c2(∞)≫Δc2>0, and both c2(∞) and Δc2 are constant. Ducted wave dispersion relations are obtained from the requirements that the earth's surface act as a rigid boundary to the atmospheric
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Propagation of the transient electromagnetic field above atmospheric surface duct
Applied Mathematics and Computation, 2003zbMATH Open Web Interface contents unavailable due to conflicting licenses.
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A narrow-angle parabolic equation model in atmospheric ducts
2016 11th International Symposium on Antennas, Propagation and EM Theory (ISAPE), 2016In this paper, the narrow-angle parabolic equation (NAPE) model applied on atmospheric ducts is solved by using the improved discrete mixed Fourier transform (IDMFT) method which is an efficient form of the split-step Fourier transform (SSFT) algorithm under the impedance boundary conditions.
Yajiao Wang, Lixin Guo, Qingliang Li
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Tracking atmospheric ducts using radar clutter: evaporation duct tracking using kalman filters
2007 IEEE Antennas and Propagation Society International Symposium, 2007This paper addresses the problem of tracking evaporation ducts in marine environments. The method tracks the evolution of the range and height-dependent index of refraction using the radar sea clutter. A split-step fast Fourier transform (FFT) based parabolic equation (PE) approximation to the wave equation is used to compute the clutter return in ...
Caglar Yardim +2 more
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The effect of atmospheric duct on modern OFDM-based digital broadcasting systems
33rd European Microwave Conference Proceedings (IEEE Cat. No.03EX723C), 2003The aim of this paper is to investigate the effect of atmospheric ducts on modern OFDM-based broadcasting systems in VHF, UHF and L bands. Full-wave parabolic equation method will be used for calculation of electromagnetic field strength in time domain.
Homayoon Oraizi, Shahram Hosseinzadeh
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