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The 2018 InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) Mission has the mission goal of providing insitu data for the first measurement of the geothermal heat flow of Mars. The Heat Flow and Physical Properties Package (HP3) will take thermal conductivity and thermal gradient measurements to approximately 5 m depth. By necessity, this measurement will be made within a few meters of the lander. This means that thermal perturbations from the lander will modify local surface and subsurface temperature measurements. For HP3’s sensitive thermal gradient measurements, this spacecraft influence will be important to model and parameterize. Here we present a basic 3D model of thermal effects of the lander on its surroundings. Though lander perturbations significantly alter subsurface temperatures, a successful thermal gradient measurement will be possible in all thermal conditions by proper (\(>3~\mbox{m}\) depth) placement of the heat flow probe.  相似文献   
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In the upcoming generation of satellite sensors, hyperspectral instruments will play a significant role. This payload type is considered world-wide within different future planning.Our team has now successfully finalized the Phase B study for the advanced hyperspectral mission EnMAP (Environmental Mapping and Analysis Programme), Germans next optical satellite being scheduled for launch in 2012. GFZ in Potsdam has the scientific lead on EnMAP, Kayser-Threde in Munich is the industrial prime.The EnMAP instrument provides over 240 continuous spectral bands in the wavelength range between 420 and 2450 nm with a ground resolution of 30 m×30 m. Thus, the broad science and application community can draw from an extensive and highly resolved pool of information supporting the modeling and optimization process on their results. The performance of the hyperspectral instrument allows for a detailed monitoring, characterization and parameter extraction of rock/soil targets, vegetation, and inland and coastal waters on a global scale supporting a wide variety of applications in agriculture, forestry, water management and geology. The operation of an airborne system (ARES) as an element in the HGF hyperspectral network and the ongoing evolution concerning data handling and extraction procedures, will support the later inclusion process of EnMAP into the growing scientist and user communities.  相似文献   
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In the phase of redefinition of the EUMETSAT ground segment seven so called Satellite Application Facilities (SAF) each of them serving dedicated user groups have been established in Europe. The SAF on climate monitoring (CM-SAF) will deliver a comprehensive set of climate variables, including from different cloud products, radiation budget at the top of the atmosphere, surface radiation budget and tropospheric humidity. A consistent dataset of cloud and radiation products in a high spatial resolution on a uniform grid is derived. The CM-SAF is a joint project of the German Meteorological Service, EUMETSAT and five other European Meteorological Services. It is dedicated to produce climate datasets using data from instruments onboard of METEOSAT Second Generation and polar orbiting satellites NOAA and METOP. After the development phase, the CM-SAF has started its initial operational phase in the end of 2003. In this context, the algorithms have been implemented at the processing centres and the processing of satellite data from the polar orbiting satellites of NOAA has commenced. This paper gives an overview of the first products of surface radiative fluxes and their validation with selected surface sites.  相似文献   
4.
During the solar journey through galactic space, variations in the physical properties of the surrounding interstellar medium (ISM) modify the heliosphere and modulate the flux of galactic cosmic rays (GCR) at the surface of the Earth, with consequences for the terrestrial record of cosmogenic radionuclides. One phenomenon that needs studying is the effect on cosmogenic isotope production of changing anomalous cosmic ray fluxes at Earth due to variable interstellar ionizations. The possible range of interstellar ram pressures and ionization levels in the low density solar environment generate dramatically different possible heliosphere configurations, with a wide range of particle fluxes of interstellar neutrals, their secondary products, and GCRs arriving at Earth. Simple models of the distribution and densities of ISM in the downwind direction give cloud transition timescales that can be directly compared with cosmogenic radionuclide geologic records. Both the interstellar data and cosmogenic radionuclide data are consistent with two cloud transitions, within the past 10,000 years and a second one 20,000–30,000 years ago, with large and assumption-dependent uncertainties. The geomagnetic timeline derived from cosmic ray fluxes at Earth may require adjustment to account for the disappearance of anomalous cosmic rays when the Sun is immersed in ionized gas.  相似文献   
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A direct fusion drive for rocket propulsion   总被引:1,自引:0,他引:1  
The Direct Fusion Drive (DFD), a compact, anuetronic fusion engine, will enable more challenging exploration missions in the solar system. The engine proposed here uses a deuterium–helium-3 reaction to produce fusion energy by employing a novel field-reversed configuration (FRC) for magnetic confinement. The FRC has a simple linear solenoid coil geometry yet generates higher plasma pressure, hence higher fusion power density, for a given magnetic field strength than other magnetic-confinement plasma devices. Waste heat generated from the plasma?s Bremsstrahlung and synchrotron radiation is recycled to maintain the fusion temperature. The charged reaction products, augmented by additional propellant, are exhausted through a magnetic nozzle. A 1 MW DFD is presented in the context of a mission to deploy the James Webb Space Telescope (6200 kg) from GPS orbit to a Sun–Earth L2 halo orbit in 37 days using just 353 kg of propellant and about half a kilogram of 3He. The engine is designed to produce 40 N of thrust with an exhaust velocity of 56.5 km/s and has a specific power of 0.18 kW/kg.  相似文献   
6.
Aymeric Spiga  Don Banfield  Nicholas A. Teanby  François Forget  Antoine Lucas  Balthasar Kenda  Jose Antonio Rodriguez Manfredi  Rudolf Widmer-Schnidrig  Naomi Murdoch  Mark T. Lemmon  Raphaël F. Garcia  Léo Martire  Özgür Karatekin  Sébastien Le Maistre  Bart Van Hove  Véronique Dehant  Philippe Lognonné  Nils Mueller  Ralph Lorenz  David Mimoun  Sébastien Rodriguez  Éric Beucler  Ingrid Daubar  Matthew P. Golombek  Tanguy Bertrand  Yasuhiro Nishikawa  Ehouarn Millour  Lucie Rolland  Quentin Brissaud  Taichi Kawamura  Antoine Mocquet  Roland Martin  John Clinton  Éléonore Stutzmann  Tilman Spohn  Suzanne Smrekar  William B. Banerdt 《Space Science Reviews》2018,214(7):109
In November 2018, for the first time a dedicated geophysical station, the InSight lander, will be deployed on the surface of Mars. Along with the two main geophysical packages, the Seismic Experiment for Interior Structure (SEIS) and the Heat-Flow and Physical Properties Package (HP3), the InSight lander holds a highly sensitive pressure sensor (PS) and the Temperature and Winds for InSight (TWINS) instrument, both of which (along with the InSight FluxGate (IFG) Magnetometer) form the Auxiliary Sensor Payload Suite (APSS). Associated with the RADiometer (RAD) instrument which will measure the surface brightness temperature, and the Instrument Deployment Camera (IDC) which will be used to quantify atmospheric opacity, this will make InSight capable to act as a meteorological station at the surface of Mars. While probing the internal structure of Mars is the primary scientific goal of the mission, atmospheric science remains a key science objective for InSight. InSight has the potential to provide a more continuous and higher-frequency record of pressure, air temperature and winds at the surface of Mars than previous in situ missions. In the paper, key results from multiscale meteorological modeling, from Global Climate Models to Large-Eddy Simulations, are described as a reference for future studies based on the InSight measurements during operations. We summarize the capabilities of InSight for atmospheric observations, from profiling during Entry, Descent and Landing to surface measurements (pressure, temperature, winds, angular momentum), and the plans for how InSight’s sensors will be used during operations, as well as possible synergies with orbital observations. In a dedicated section, we describe the seismic impact of atmospheric phenomena (from the point of view of both “noise” to be decorrelated from the seismic signal and “signal” to provide information on atmospheric processes). We discuss in this framework Planetary Boundary Layer turbulence, with a focus on convective vortices and dust devils, gravity waves (with idealized modeling), and large-scale circulations. Our paper also presents possible new, exploratory, studies with the InSight instrumentation: surface layer scaling and exploration of the Monin-Obukhov model, aeolian surface changes and saltation / lifing studies, and monitoring of secular pressure changes. The InSight mission will be instrumental in broadening the knowledge of the Martian atmosphere, with a unique set of measurements from the surface of Mars.  相似文献   
7.
As personal mobility increases, people spend more time in their vehicles. Furthermore, a large segment of today's workforce is part of a growing mobile service industry. This mobile society creates opportunities to increase productivity which do not yet exist. Today's commuting time could be better utilized and mobile business transactions could be more efficiently conducted, by integrating mobile IP wireless services in vehicles. By means of a direct to mobile user Internet access, and total IP services, integrated into automobiles, S@tMax services can empower the mobile business movement therefore improving productivity. This paper presents a commercial system architecture that will deliver an optimized solution for direct to mobile user Internet access, through an integration of a ground based network infrastructure, use of existing communications satellites and the development of a proprietary satellite system. As a result of a detailed systems engineering process, the architectures of the space, ground and infrastructures segments will be presented. Furthermore, the benefits of on-orbit servicing were examined in the S@tMax context. The approach proposed is considered as an important step towards enforcing main roadway IP coverage in the US, for near-continuous communications and services.  相似文献   
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