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101.
Mitchell R.L. Mcpherson D.A. 《IEEE transactions on aerospace and electronic systems》1981,(4):553-560
A general procedure is given for generating infinite-length random sequences defined by a short-term power spectral density that is slowly time varying. Any shape of a power spectral density can be accommodated, including those that cover a wide dynamic range, and any smooth type of nonstationarity can be accommodated. The procedure is based on digital processing techniques. However, it can be extended to the generation of analog signals. Several examples are given, both for digital and analog signals. 相似文献
102.
103.
The Jupiter Energetic Particle Detector Instrument (JEDI) Investigation for the Juno Mission 总被引:1,自引:0,他引:1
B. H. Mauk D. K. Haggerty S. E. Jaskulek C. E. Schlemm L. E. Brown S. A. Cooper R. S. Gurnee C. M. Hammock J. R. Hayes G. C. Ho J. C. Hutcheson A. D. Jacques S. Kerem C. K. Kim D. G. Mitchell K. S. Nelson C. P. Paranicas N. Paschalidis E. Rossano M. R. Stokes 《Space Science Reviews》2017,213(1-4):289-346
The Jupiter Energetic Particle Detector Instruments (JEDI) on the Juno Jupiter polar-orbiting, atmosphere-skimming, mission to Jupiter will coordinate with the several other space physics instruments on the Juno spacecraft to characterize and understand the space environment of Jupiter’s polar regions, and specifically to understand the generation of Jupiter’s powerful aurora. JEDI comprises 3 nearly-identical instruments and measures at minimum the energy, angle, and ion composition distributions of ions with energies from H:20 keV and O: 50 keV to >1 MeV, and the energy and angle distribution of electrons from <40 to >500 keV. Each JEDI instrument uses microchannel plates (MCP) and thin foils to measure the times of flight (TOF) of incoming ions and the pulse height associated with the interaction of ions with the foils, and it uses solid state detectors (SSD’s) to measure the total energy (E) of both the ions and the electrons. The MCP anodes and the SSD arrays are configured to determine the directions of arrivals of the incoming charged particles. The instruments also use fast triple coincidence and optimum shielding to suppress penetrating background radiation and incoming UV foreground. Here we describe the science objectives of JEDI, the science and measurement requirements, the challenges that the JEDI team had in meeting these requirements, the design and operation of the JEDI instruments, their calibrated performances, the JEDI inflight and ground operations, and the initial measurements of the JEDI instruments in interplanetary space following the Juno launch on 5 August 2011. Juno will begin its prime science operations, comprising 32 orbits with dimensions 1.1×40 RJ, in mid-2016. 相似文献
104.
105.
The importance of solar cells for space power supplies continues with increased emphasis. The need for advances in the design of solar cell arrays becomes more pressing as the requirement for increased power levels is apparent. This paper discusses a flexible solar cell concept, includes a brief history of the development, describes a conceptual design for a 20-kW array, giving weight breakdown, and describes an existing design effort. 相似文献
106.
M. Horányi V. Hoxie D. James A. Poppe C. Bryant B. Grogan B. Lamprecht J. Mack F. Bagenal S. Batiste N. Bunch T. Chanthawanich F. Christensen M. Colgan T. Dunn G. Drake A. Fernandez T. Finley G. Holland A. Jenkins C. Krauss E. Krauss O. Krauss M. Lankton C. Mitchell M. Neeland T. Reese K. Rash G. Tate C. Vaudrin J. Westfall 《Space Science Reviews》2008,140(1-4):387-402
The Student Dust Counter (SDC) experiment of the New Horizons Mission is an impact dust detector to map the spatial and size distribution of dust along the trajectory of the spacecraft across the solar system. The sensors are thin, permanently polarized polyvinylidene fluoride (PVDF) plastic films that generate an electrical signal when dust particles penetrate their surface. SDC is capable of detecting particles with masses m>10?12 g, and it has a total sensitive surface area of about 0.1 m2, pointing most of the time close to the ram direction of the spacecraft. SDC is part of the Education and Public Outreach (EPO) effort of this mission. The instrument was designed, built, tested, integrated, and now is operated by students. 相似文献
107.
The Pluto Energetic Particle Spectrometer Science Investigation (PEPSSI) on the New Horizons Mission
Ralph L. McNutt Jr. Stefano A. Livi Reid S. Gurnee Matthew E. Hill Kim A. Cooper G. Bruce Andrews Edwin P. Keath Stamatios M. Krimigis Donald G. Mitchell Barry Tossman Fran Bagenal John D. Boldt Walter Bradley William S. Devereux George C. Ho Stephen E. Jaskulek Thomas W. LeFevere Horace Malcom Geoffrey A. Marcus John R. Hayes G. Ty Moore Nikolaos P. Paschalidis Mark E. Perry Bruce D. Williams Paul Wilson IV Lawrence E. Brown Martha B. Kusterer Jon D. Vandegriff 《Space Science Reviews》2009,145(3-4):381-381
108.
M. Sasaki S. Haino K. Abe H. Fuke T. Hams K.C. Kim M.H. Lee Y. Makida S. Matsuda J.W. Mitchell A.A. Moiseev J. Nishimura M. Nozaki S. Orito J.F. Ormes T. Sanuki E.S. Seo Y. Shikaze R.E. Streitmatter J. Suzuki K. Tanaka T. Yamagami A. Yamamoto T. Yoshida K. Yoshimura 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2008
In this paper, we report searches for antihelium in cosmic rays using two recently flown magnetic rigidity spectrometers. BESS-TeV had extended rigidity with an MDR of 1.4 TV and had a flight duration of one day. BESS-Polar was optimized for collecting power. It was flown for 8.5 days and had an MDR of 240 GV. The former flight allows us to explore a previously unexplored rigidity band and the latter flight yields a factor of three improvement in the overall BESS limit. No antihelium candidate was found in the rigidity ranges of 1–500 GV, and 0.6–20 GV, among 7 × 104 events taken with BESS-TeV, and 8 × 106 events taken with BESS-Polar, respectively. 相似文献
109.
K.C. Kim K. Abe H. Fuke T. Hams M.H. Lee Y. Makida S. Matsuda J.W. Mitchell J. Nishimura J.F. Ormes M. Sasaki E.S. Seo Y. Shikaze R.E. Streitmatter J. Suzuki K. Tanaka T. Yamagami A. Yamamoto T. Yoshida K. Yoshimura 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2013
The Balloon-borne Experiment with a Superconducting Spectrometer (BESS) was flown from Lynn Lake, Manitoba, Canada in August, 2000, during the maximum solar modulation period, with an average residual atmospheric overburden of 4.3 g/cm2. Precise spectral measurements of cosmic ray hydrogen isotopes from 0.178 GeV/n to 1.334 GeV/n were made during the 28.7 h of flight. This paper presents the measured energy spectra and their ratio, 2H/1H. The results are also compared with previous measurements and theoretical predictions. 相似文献
110.
High energy neutral atom (hena) imager for the IMAGE mission 总被引:1,自引:0,他引:1
Mitchell D.G. Jaskulek S.E. Schlemm C.E. Keath E.P. Thompson R.E. Tossman B.E. Boldt J.D. Hayes J.R. Andrews G.B. Paschalidis N. Hamilton D.C. Lundgren R.A. Tums E.O. Wilson P. Voss H.D. Prentice D. Hsieh K.C. Curtis C.C. Powell F.R. 《Space Science Reviews》2000,91(1-2):67-112
The IMAGE mission will be the first of its kind, designed to comprehensively image a variety of emissions from the Earth's magnetosphere, with sufficient time resolution to follow the dynamics associated with the development of magnetospheric storms. Energetic neutral atoms (ENA) emitted from the ring current during storms are one of the key emissions that will be imaged. This paper describes the characteristics of the High Energy Neutral Atom imager, HENA. Using pixelated solid state detectors, imaging microchannel plates, electron optics, and time of flight electronics, HENA is designed to return images of the ENA emitting regions of the inner magnetosphere with 2 minute time resolution, at angular resolution of 8 degrees or better above the energy of 50 keV/nucleon. HENA will also image separately the emissions in hydrogen, helium, and oxygen above 30 keV/nucleon. HENA will reject energetic ions below 200 keV/charge, allowing ENA images to be returned in the presence of ambient energetic ions. HENA images will reveal the distribution and the evolution of energetic ion distributions as they are injected into the ring current during geomagnetic storms, as they drift about the Earth on both open and closed drift paths, and as they decay through charge exchange to pre-storm levels. Substorm ion injections will also be imaged, as will the regions of low altitude, high latitude ion precipitation into the upper atmosphere. 相似文献