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The Miniature Radio Frequency (Mini-RF) system is manifested on the Lunar Reconnaissance Orbiter (LRO) as a technology demonstration and an extended mission science instrument. Mini-RF represents a significant step forward in spaceborne RF technology and architecture. It combines synthetic aperture radar (SAR) at two wavelengths (S-band and X-band) and two resolutions (150 m and 30 m) with interferometric and communications functionality in one lightweight (16 kg) package. Previous radar observations (Earth-based, and one bistatic data set from Clementine) of the permanently shadowed regions of the lunar poles seem to indicate areas of high circular polarization ratio (CPR) consistent with volume scattering from volatile deposits (e.g. water ice) buried at shallow (0.1–1 m) depth, but only at unfavorable viewing geometries, and with inconclusive results. The LRO Mini-RF utilizes new wideband hybrid polarization architecture to measure the Stokes parameters of the reflected signal. These data will help to differentiate “true” volumetric ice reflections from “false” returns due to angular surface regolith. Additional lunar science investigations (e.g. pyroclastic deposit characterization) will also be attempted during the LRO extended mission. LRO’s lunar operations will be contemporaneous with India’s Chandrayaan-1, which carries the Forerunner Mini-SAR (S-band wavelength and 150-m resolution), and bistatic radar (S-Band) measurements may be possible. On orbit calibration, procedures for LRO Mini-RF have been validated using Chandrayaan 1 and ground-based facilities (Arecibo and Greenbank Radio Observatories).  相似文献   
2.
The ultraviolet spectrograph instrument on the Juno mission (Juno-UVS) is a long-slit imaging spectrograph designed to observe and characterize Jupiter’s far-ultraviolet (FUV) auroral emissions. These observations will be coordinated and correlated with those from Juno’s other remote sensing instruments and used to place in situ measurements made by Juno’s particles and fields instruments into a global context, relating the local data with events occurring in more distant regions of Jupiter’s magnetosphere. Juno-UVS is based on a series of imaging FUV spectrographs currently in flight—the two Alice instruments on the Rosetta and New Horizons missions, and the Lyman Alpha Mapping Project on the Lunar Reconnaissance Orbiter mission. However, Juno-UVS has several important modifications, including (1) a scan mirror (for targeting specific auroral features), (2) extensive shielding (for mitigation of electronics and data quality degradation by energetic particles), and (3) a cross delay line microchannel plate detector (for both faster photon counting and improved spatial resolution). This paper describes the science objectives, design, and initial performance of the Juno-UVS.  相似文献   
3.
The MESSENGER Science Operations Center (SOC) is an integrated set of subsystems and personnel whose purpose is to obtain, provide, and preserve the scientific measurements and analysis that fulfill the objectives of the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission. The SOC has two main functional areas. The first is to facilitate science instrument planning and operational activities, including related spacecraft guidance and control operations, and to work closely with the Mission Operations Center to implement those plans. The second functional area, data management and analysis, involves the receipt of science-related telemetry, reformatting and cataloging this telemetry and related ancillary information, retaining the science data for use by the MESSENGER Science Team, and preparing data archives for delivery to the Planetary Data System; and the provision of operational assistance to the instrument and science teams in executing their algorithms and generating higher-level data products.  相似文献   
4.
We present the preliminary results of the recent Hα narrow-band imaging carried out for NGC 2770 with the Gran Telescopio Canarias (GTC) equipped with OSIRIS. We put the polarization measurements reported in Gorosabel et al. (2010) for SN 2007uy and SN 2008D in the context of the morphological information inferred from the Hα imaging. We estimated the orientation of the interstellar polarization (ISP) at the position of SN 2007uy and, most interestingly, at the site of SN 2008D which has been subject of an intensive debate due to its possible connection with Gamma-Ray Bursts (GRBs). The Hα imaging reveals a clumpy interstellar medium (ISM) composed of hundreds of compact emitting regions, for which we determined their sizes. The derived size for the Hα emitting region coincident with SN 2008D is consistent with the ISM cell size limits imposed by Gorosabel et al. (2010) based on millimetric data. A deeper data analysis is under way and will be published elsewhere. This article represents the first attempt to study the site of a possible GRB-like event combining millimetric, polarimetric and narrow-band data.  相似文献   
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