共查询到20条相似文献,搜索用时 15 毫秒
1.
E. Taylor P. Harvey M. Ludlam P. Berg R. Abiad D. Gordon 《Space Science Reviews》2008,141(1-4):153-169
The Time History of Events and Macroscale Interactions during Substorms (THEMIS) mission is a NASA Medium-class Explorer (MIDEX) mission, launched on February 17, 2007. The mission employs five identical micro-satellites, or “probes,” which line-up along the Earth’s magnetotail every four days in conjunctions to determine the trigger and large-scale evolution of magnetic substorms. The probes are equipped with a comprehensive suite of instruments that measure and track the motion of thermal and super-thermal ions and electrons, and electric and magnetic fields, at key regions in the magnetosphere. Primary science objectives require high data rates at periods of scientific interest, large data volumes, and control of science data collection on suborbital time scales. A central Instrument Data Processing Unit (IDPU) is necessary to organize and prioritize the data from the large number of instruments into a 200 MB solid state memory. The large data volume produced by the instruments requires a flexible memory capable of both high resolution snapshots during conjunctions and coarser survey data collection throughout the orbit. Onboard triggering algorithms select and prioritize the snapshots based on data quality to optimize the science data that is returned to the ground. This paper presents a detailed discussion of the hardware and software design of the THEMIS IDPU, describing the heritage design that has been fundamental to the THEMIS mission success so far. 相似文献
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Ergun R.E. Carlson C.W. Mozer F.S. Delory G.T. Temerin M. McFadden J.P. Pankow D. Abiad R. Harvey P. Wilkes R. Primbsch H. Elphic R. Strangeway R. Pfaff R. Cattell C.A. 《Space Science Reviews》2001,98(1-2):67-91
We describe the electric field sensors and electric and magnetic field signal processing on the FAST (Fast Auroral SnapshoT) satellite. The FAST satellite was designed to make high time resolution observations of particles and electromagnetic fields in the auroral zone to study small-scale plasma interactions in the auroral acceleration region. The DC and AC electric fields are measured with three-axis dipole antennas with 56 m, 8 m, and 5 m baselines. A three-axis flux-gate magnetometer measures the DC magnetic field and a three-axis search coil measures the AC magnetic field. A central signal processing system receives all signals from the electric and magnetic field sensors. Spectral coverage is from DC to 4 MHz. There are several types of processed data. Survey data are continuous over the auroral zone and have full-orbit coverage for fluxgate magnetometer data. Burst data include a few minutes of a selected region of the auroral zone at the highest time resolution. A subset of the burst data, high speed burst memory data, are waveform data at 2×106 sample s–1. Electric field and magnetic field data are primarily waveforms and power spectral density as a function of frequency and time. There are also various types of focused data processing, including cross-spectral analysis, fine-frequency plasma wave tracking, high-frequency polarity measurement, and wave-particle correlations. 相似文献
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The Energetic Particle and Plasma Spectrometer Instrument on the MESSENGER Spacecraft 总被引:1,自引:0,他引:1
G. Bruce Andrews Thomas H. Zurbuchen Barry H. Mauk Horace Malcom Lennard A. Fisk George Gloeckler George C. Ho Jeffrey S. Kelley Patrick L. Koehn Thomas W. LeFevere Stefano S. Livi Robert A. Lundgren Jim M. Raines 《Space Science Reviews》2007,131(1-4):523-556
The Energetic Particle and Plasma Spectrometer (EPPS) package on the MErcury Surface, Space ENvironment, GEochemistry, and
Ranging (MESSENGER) mission to Mercury is composed of two sensors, the Energetic Particle Spectrometer (EPS) and the Fast
Imaging Plasma Spectrometer (FIPS). EPS measures the energy, angular, and compositional distributions of the high-energy components
of the in situ electrons (>20 keV) and ions (>5 keV/nucleon), while FIPS measures the energy, angular, and compositional distributions
of the low-energy components of the ion distributions (<50 eV/charge to 20 keV/charge). Both EPS and FIPS have very small
footprints, and their combined mass (∼3 kg) is significantly lower than that of comparable instruments. 相似文献
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本文介绍了采用ANDOVER楼宇自控系统中,自行研制开发的数据采集器的硬件设计原理及与上位机接口软件的原理,该系统已用于实际,效果良好。 相似文献
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以单片机为核心的智能化仪器难以实现高精确度、大范围测量,尤其是输出量与输入量在不同区间呈不同的函数关系时,在单片机上难以实现其运算,为此本文把输出量划分为若干个区间段,在不同区间段内采用多项式校正理论和最小二乘法拟合方法,给出了在不同区间段内多项式校正的数学模型,并在此基础上阐述了提高校正数据精度的有效措施。 相似文献
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Valerie C. Thomas Joseph M. Makowski G. Mark Brown John F. McCarthy Dominick Bruno J. Christopher Cardoso W. Michael Chiville Thomas F. Meyer Kenneth E. Nelson Betina E. Pavri David A. Termohlen Michael D. Violet Jeffrey B. Williams 《Space Science Reviews》2011,163(1-4):175-249
The Dawn spacecraft is designed to travel to and operate in orbit around the two largest main belt asteroids, Vesta and Ceres. Developed to meet a ten-year life and fully redundant, the spacecraft accommodates an ion propulsion system, including three ion engines and xenon propellant tank, utilizes large solar arrays to power the engines, carries the science instrument payload, and hosts the hardware and software required to successfully collect and transmit the scientific data back to Earth. The launch of the Dawn spacecraft in September 2007 from Cape Canaveral Air Force Station was the culmination of nearly five years of design, development, integration and testing of this unique system, one of the very few scientific spacecraft to rely on ion propulsion. The Dawn spacecraft arrived at its first destination, Vesta, in July 2011, where it will conduct science operations for twelve months before departing for Ceres. 相似文献
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James C. Leary Richard F. Conde George Dakermanji Carl S. Engelbrecht Carl J. Ercol Karl B. Fielhauer David G. Grant Theodore J. Hartka Tracy A. Hill Stephen E. Jaskulek Mary A. Mirantes Larry E. Mosher Michael V. Paul David F. Persons Elliot H. Rodberg Dipak K. Srinivasan Robin M. Vaughan Samuel R. Wiley 《Space Science Reviews》2007,131(1-4):187-217
The MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft was designed and constructed to withstand the harsh environments associated with achieving and operating in Mercury
orbit. The system can be divided into eight subsystems: structures and mechanisms (e.g., the composite core structure, aluminum
launch vehicle adapter, and deployables), propulsion (e.g., the state-of-the-art titanium fuel tanks, thruster modules, and
associated plumbing), thermal (e.g., the ceramic-cloth sunshade, heaters, and radiators), power (e.g., solar arrays, battery,
and controlling electronics), avionics (e.g., the processors, solid-state recorder, and data handling electronics), software
(e.g., processor-supported code that performs commanding, data handling, and spacecraft control), guidance and control (e.g.,
attitude sensors including star cameras and Sun sensors integrated with controllers including reaction wheels), radio frequency
telecommunications (e.g., the spacecraft antenna suites and supporting electronics), and payload (e.g., the science instruments
and supporting processors). This system architecture went through an extensive (nearly four-year) development and testing
effort that provided the team with confidence that all mission goals will be achieved.
Larry E. Mosher passed away during the preparation of this paper. 相似文献
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详述了DOR(差分单向测距)信号的本地相关处理方法。首先根据轨道预报确定先验时延模型值,利用高精度频率估算方法估计航天器DOR信号的星上发射频率,然后通过时延模型值与频率估计值构造DOR本地模型信号,再将此模型信号分别与测站接收的DOR实测信号进行互相关运算,提取相关相位,解算高精度时延观测量。推导了DOR信号本地相关处理的数学模型,通过信号仿真验证了该方法的有效性,在仅考虑系统噪声影响与轨道预报误差的条件下,仿真时延测量精度达到0.1 ns,为深空航天器精密轨道测量提供了一种可借鉴的技术方法。 相似文献
12.
The New Horizons Spacecraft 总被引:1,自引:0,他引:1
Glen H. Fountain David Y. Kusnierkiewicz Christopher B. Hersman Timothy S. Herder Thomas B. Coughlin William C. Gibson Deborah A. Clancy Christopher C. DeBoy T. Adrian Hill James D. Kinnison Douglas S. Mehoke Geffrey K. Ottman Gabe D. Rogers S. Alan Stern James M. Stratton Steven R. Vernon Stephen P. Williams 《Space Science Reviews》2008,140(1-4):23-47
The New Horizons spacecraft was launched on 19 January 2006. The spacecraft was designed to provide a platform for seven instruments designated by the science team to collect and return data from Pluto in 2015. The design meets the requirements established by the National Aeronautics and Space Administration (NASA) Announcement of Opportunity AO-OSS-01. The design drew on heritage from previous missions developed at The Johns Hopkins University Applied Physics Laboratory (APL) and other missions such as Ulysses. The trajectory design imposed constraints on mass and structural strength to meet the high launch acceleration consistent with meeting the AO requirement of returning data prior to the year 2020. The spacecraft subsystems were designed to meet tight resource allocations (mass and power) yet provide the necessary control and data handling finesse to support data collection and return when the one-way light time during the Pluto fly-by is 4.5 hours. Missions to the outer regions of the solar system (where the solar irradiance is 1/1000 of the level near the Earth) require a radioisotope thermoelectric generator (RTG) to supply electrical power. One RTG was available for use by New Horizons. To accommodate this constraint, the spacecraft electronics were designed to operate on approximately 200 W. The travel time to Pluto put additional demands on system reliability. Only after a flight time of approximately 10 years would the desired data be collected and returned to Earth. This represents the longest flight duration prior to the return of primary science data for any mission by NASA. The spacecraft system architecture provides sufficient redundancy to meet this requirement with a probability of mission success of greater than 0.85. The spacecraft is now on its way to Pluto, with an arrival date of 14 July 2015. Initial in-flight tests have verified that the spacecraft will meet the design requirements. 相似文献
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介绍了斜面的测量和计算机处理数据的方法,主要研究最小二乘原理下的数据处理,应用C语言编程处理,大大提高了斜面测量的精度和运算速度。同时提出基于最小二乘法处理的数学模型,给出相应的程序框图。 相似文献
14.
基于航空卫星通信的飞行监视,即自动相关监视(ADS),是航空卫星移动业务(AMSS)通信应用新领域,是建立在航空卫星通信基础上的一种新的飞行监视技术。该文介绍了基本ADS报告信息电文的组成及各部分的含义,着重阐述将所收到的ADS数据进行处理,并以直观易懂的表格及图象形式显示出来,便于确切地知道飞机的四维位置(纬度、经度、高度和时间)。 相似文献
15.
为了进一步提高脉冲等离子体推力器点火的可靠性和使用寿命,采用理论计算和地面试验的方法,设计了一款可应用于立方体纳卫星脉冲等离子体推力器放电能量为2.6J的电源处理单元,其放电点火电路是基于LC振荡电路,且对放电点火电路的性能、开关管的电流应力和整个电源处理单元的稳定可靠性进行了研究。结果表明:LC振荡放电点火电路中,开关器件的电流应力较小,提高了整个电路的可靠性;该放电点火电路在输入电压800V时,点火电流的峰值可达到100A~150A,这种大电流放电有助于清除火花塞表面的积碳。 相似文献
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利用NI 的PXI-6281高速数据采集卡来完成角速度波动信号的采集,借鉴信号失真度的概念,分析角速度反馈信号的基波和高次谐波大小,求取高次谐波与基波幅值比,作为角速度波动率. 相似文献
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从航空发动机压气机叶片型面检测的传统方法及特点出发,简单介绍了激光测量仪总体系统,重点阐述了处理系统软件的设计,并将其应用于实践中。 相似文献
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现代GPU不仅是功能强劲的图形处理引擎,也是具有强大计算性能和存储带宽的高度并行可编程器件,能够与CPU构建完整的异构处理系统。而将GPU用于图形处理以外的计算,一般称之为GPU通用计算(General-Purpose computing on Graphics Processing Unit,GPGPU)。对GPU通用计算的概念及分类、硬件架构及工作机制、软件环境及处理模型进行详细的研究,期望为GPU通用计算在航空嵌入式计算领域的进一步应用提供参考。 相似文献
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与传统单级整体叶盘相比,新型整体多级盘毂转子单元体加工技术是将轴颈、盘及毂筒作为一个零件进行单元体整体加工,避免了单个零件安装和焊接结构带来的诸多缺点。具有减重、增效和提高可靠性等优点。本文从工艺路线的安排、工装和刀具的设计、加工变形有限元法预估、高速轻载荷切削四方面入手,总结出一套针对此类零件的加工方法,具有重要的指导意义。 相似文献