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Neugebauer M. Steinberg J.T. Tokar R.L. Barraclough B.L. Dors E.E. Wiens R.C. Gingerich D.E. Luckey D. Whiteaker D.B. 《Space Science Reviews》2003,105(3-4):661-679
Some of the objectives of the Genesis mission require the separate collection of solar wind originating in different types
of solar sources. Measurements of the solar wind protons, alpha particles, and electrons are used on-board the spacecraft
to determine whether the solar-wind source is most likely a coronal hole, interstream flow, or a coronal mass ejection. A
simple fuzzy logic scheme operating on measurements of the proton temperature, the alpha-particle abundance, and the presence
of bidirectional streaming of suprathermal electrons was developed for this purpose. Additional requirements on the algorithm
include the ability to identify the passage of forward shocks, reasonable levels of hysteresis and persistence, and the ability
to modify the algorithm by changes in stored constants rather than changes in the software. After a few minor adjustments,
the algorithm performed well during the initial portion of the mission.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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Barraclough B.L. Dors E.E. Abeyta R.A. Alexander J.F. Ameduri F.P. Baldonado J.R. Bame S.J. Casey P.J. Dirks G. Everett D.T. Gosling J.T. Grace K.M. Guerrero D.R. Kolar J.D. Kroesche J.L. Lockhart W.L. McComas D.J. Mietz D.E. Roese J. Sanders J. Steinberg J.T. Tokar R.L. Urdiales C. Wiens R.C. 《Space Science Reviews》2003,105(3-4):627-660
The Genesis Ion Monitor (GIM) and the Genesis Electron Monitor (GEM) provide 3-dimensional plasma measurements of the solar
wind for the Genesis mission. These measurements are used onboard to determine the type of plasma that is flowing past the
spacecraft and to configure the solar wind sample collection subsystems in real-time. Both GIM and GEM employ spherical-section
electrostatic analyzers followed by channel electron multiplier (CEM) arrays for detection and angle and energy/charge analysis
of incident ions and electrons. GIM is of a new design specific to Genesis mission requirements whereas the GEM sensor is
an almost exact copy of the plasma electron sensors currently flying on the ACE and Ulysses spacecraft, albeit with new electronics
and programming. Ions are detected at forty log-spaced energy levels between ∼ 1 eV and 14 keV by eight CEM detectors, while
electrons with energies between ∼ 1 eV and 1.4 keV are measured at twenty log-spaced energy levels using seven CEMs. The spin
of the spacecraft is used to sweep the fan-shaped fields-of-view of both instruments across all areas of the sky of interest,
with ion measurements being taken forty times per spin and samples of the electron population being taken twenty four times
per spin. Complete ion and electron energy spectra are measured every ∼ 2.5 min (four spins of the spacecraft) with adequate
energy and angular resolution to determine fully 3-dimensional ion and electron distribution functions. The GIM and GEM plasma
measurements are principally used to enable the operational solar wind sample collection goals of the Genesis mission but
they also provide a potentially very useful data set for studies of solar wind phenomena, especially if combined with other
solar wind data sets from ACE, WIND, SOHO and Ulysses for multi-spacecraft investigations.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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