排序方式: 共有9条查询结果,搜索用时 15 毫秒
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S. Carbone L.F. Padilha M.B. Rosa D.K. Pinheiro N.J. Schuch 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2006,37(12):2178-II
The first estimations of the aerosol optical thickness (AOT) using Langley Method at Southern Space Observatory (SSO) at Southern Brazil (29.4°S, 53.8°W) are presented. In addition to ozone and sulphur dioxide columns, AOT can be obtained using Brewer Spectrophotometer at specific wavelengths: 306.3, 310.1, 313.5, 316.8 and 320.1 nm. The AOT was obtained for the period from November/2002 to May/2003. Very low AOT averages were obtained, whose values were about 0.21 ± 0.03 at 306.3 nm, 0.21 ± 0.02 at 310.1 nm, 0.19 ± 0.02 at 313.5 nm, 0.20 ± 0.02 at 316.8 nm and 0.20 ± 0.02 at 320.0 nm for all period analysed. Different behaviour of AOT were obtained at two daily specific periods of aerosol accumulation, one in the afternoons from November/2002 to February/2003, caused mainly by a mild biomass burning season’s in the region and other in the mornings from March to May/2003, due the high relative humidity presented in the region studied. 相似文献
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W. Menn O. Adriani G.C. Barbarino G.A. Bazilevskaya R. Bellotti M. Boezio E.A. Bogomolov L. Bonechi M. Bongi V. Bonvicini S. Borisov S. Bottai A. Bruno F. Cafagna D. Campana R. Carbone P. Carlson M. Casolino G. Castellini L. Consiglio M.P. De Pascale C. De Santis N. De Simone V. Di Felice A.M. Galper W. Gillard L. Grishantseva G. Jerse A.V. Karelin S.V. Koldashov S.Y. Krutkov A.N. Kvashnin A. Leonov V. Malakhov V. Malvezzi L. Marcelli A.G. Mayorov V.V. Mikhailov E. Mocchiutti A. Monaco N. Mori N. Nikonov G. Osteria F. Palma P. Papini M. Pearce P. Picozza C. Pizzolotto M. Ricci S.B. Ricciarini 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2013
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Massimo Materassi Lucilla Alfonsi Giorgiana De Franceschi Vincenzo Romano Cathryn Mitchell Paolo Spalla 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2009
The study of amplitude scintillation on GPS radio links is usually done after detrending the time series of the transmitted power so to define scintillations as the chaotic fluctuation around a unitary value. In a sense, the choice of how to detrend the time series is part of the definition of scintillation. 相似文献
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Roberto Bruno Bruno Bavassano Raffaella D’amicis Vincenzo Carbone Luca Sorriso-Valvo Ermanno Pietropaolo 《Space Science Reviews》2006,122(1-4):321-328
The observations at different solar distances and latitudes, collected in the past three decades, and the results obtained
from more and more sophisticated numerical simulations allowed us to reach a good understanding on many aspects of the complex
phenomenon of solar wind turbulence. Moreover, new interesting insights in the theory of turbulence have been obtained, in
the past decade, from the point of view that considers a turbulent flow as a complex system, where chaotic behavior and well-established
scaling laws coexist. This review aims to provide a quick overview on the state of art in this research field with particular
focus on local generation mechanisms. 相似文献
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Paolo Dabove Vincenzo Di Pietra 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2019,63(1):94-102
The possibility to access undifferenced and uncombined Global Navigation Satellite System (GNSS) measurements on smart devices with an Android operating system allows us to manage pseudorange and carrier-phase measurements to increase the accuracy of real-time positioning. The goal is to perform real-time kinematic network positioning with smartphones, evaluating the positioning accuracy regarding an external mass-market device. The positioning of Samsung Galaxy S8+ and Huawei P10 plus smartphones was performed using a dedicated tool developed by the authors, considering a continuous operating reference station (CORS) network with a mean inter-station distance of about 50?km. The same positioning technique was also applied to an external GNSS low-cost single-frequency receiver (u-blox EVK-M8T) to compare performance between the receiver and antenna embedded in the previous smartphones and this low-cost receiver coupled with a mass-market antenna (Garmin GA38). Attention was also focused on the phase ambiguity resolution, that it is still a challenging aspect for mass-market devices: even if the two smartphones provide slightly different results, the accuracy obtainable today is greater than 60?cm with a precision of few centimetres in real-time, if a CORS network is available. For real-time applications using portable devices, decimetre-level accuracy is sufficient for many applications, such as rapid mapping and search and rescue activities: these results will open new frontiers in terms of real-time positioning with portable low-cost devices. 相似文献
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Andrea Kunder Elena Valenti Massimo Dall’Ora Pawel Pietrukowicz Chris Sneden Giuseppe Bono Vittorio F. Braga Ivan Ferraro Giuliana Fiorentino Giacinto Iannicola Marcella Marconi Clara E. Martínez-Vázquez Matteo Monelli Ilaria Musella Vincenzo Ripepi Maurizio Salaris Peter B. Stetson 《Space Science Reviews》2018,214(5):90
Here we review the efforts of a number of recent results that use old tracers to understand the build up of the Galaxy. Details that lead directly to using these old tracers to measure distances are discussed. We concentrate on the following: (1) the structure and evolution of the Galactic bulge and inner Galaxy constrained from the dynamics of individual stars residing therein; (2) the spatial structure of the old Galactic bulge through photometric observations of RR Lyrae-type stars; (3) the three-dimensional structure, stellar density, mass, chemical composition, and age of the Milky Way bulge as traced by its old stellar populations; (4) an overview of RR Lyrae stars known in the ultra-faint dwarfs and their relation to the Galactic halo; and (5) different approaches for estimating absolute and relative cluster ages. 相似文献
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We briefly discuss the strong intermittent nature of the interplanetary magnetic field, observing that similarity between
its statistical properties and the passive scalar ones exists, and may arise from different dynamical mechanisms. 相似文献
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Vincenzo Della Corte Pasquale Palumbo Alessandra Rotundi Simone De Angelis Frans J. M. Rietmeijer Ezio Bussoletti Alessandra Ciucci Marco Ferrari Valentina Galluzzi Ernesto Zona 《Space Science Reviews》2012,169(1-4):159-180
DUSTER (Dust from the Upper Stratosphere Tracking Experiment and Retrieval) is an instrument designed to collect nanometer to micrometer scale solid aerosol particles in the upper stratosphere on board balloons. With three DUSTER flights we have demonstrated that: (1) the instrument’s performance was within the design parameters of environmental specifications (?80 °C; 3–10?mbar); (2) inertial impact collection of aerosols ~500?nm to 24 microns on holey-carbon thin films mounted on Transmission Electron Microscope mesh grids was achieved; (3) the design of an active collector exposed to the air flux and an identical collector “blank”, not exposed to the air flux, to monitor possible contamination permits unambiguous identification of collected particles; (4) save storage of collected samples and subsequent retrieval in the laboratory was achieved with no measurable contamination; (5)?reduced sample manipulation allowed the chemical and structural characterization of collected dust particles by Field-emission scanning electron microscopy and energy dispersive X-Ray analyses, and infrared and Raman micro-spectroscopy. The main and most ambitious goal is the collection and characterization of solid aerosol particles smaller than 3 microns of solar system debris that are currently not sampled on a routine basis by other instruments in the upper stratosphere. DUSTER will provide a record of the amount of solid aerosols, their size, shapes and chemical properties in the upper stratosphere, including particles less than 3 microns in size. The DUSTER program identified 25 particles as collected during the 2008 flight with sizes in the range of 0.4 to 24 microns. 相似文献
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Biagio Forte Massimo Materassi Lucilla Alfonsi Vincenzo Romano Giorgiana De Franceschi Paolo Spalla 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2011
Transionospheric radio signals may experience fluctuations in their amplitude and phase due to irregularity in the spatial electron density distribution, referred to as scintillation. Ionospheric scintillation is responsible for transionospheric signal degradation that can affect the performance of satellite based navigation systems. Usually, the scintillation activity is measured by means of indices such as the normalised standard deviation of the received intensity S4 and the standard deviation of the received phase σ? typically calculated over 1 min of data. Data from a GPS scintillation monitor based on 50 Hz measurements recorded at Dirigibile Italia Station (Ny-Alesund, Svalbard), in the frame of the ISACCO project ( De Franceschi et al., 2006) are used to investigate possible adoption of an alternative parameter for the estimate of phase fluctuations: i.e., the standard deviation of the phase rate of change S?. This parameter is shown to better correlate with S4 being much less detrending dependent than σ?. The couple (S4, S?) should be then considered a more physical proxy of radio scintillation than the couple (S4, σ?). 相似文献
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