R. P. Lepping  M. H. Acũna  L. F. Burlaga  W. M. Farrell  J. A. Slavin  K. H. Schatten  F. Mariani  N. F. Ness  F. M. Neubauer  Y. C. Whang  J. B. Byrnes  R. S. Kennon  P. V. Panetta  J. Scheifele  E. M. Worley 《Space Science Reviews》1995,71(1-4):207-229

The magnetic field experiment on WIND will provide data for studies of a broad range of scales of structures and fluctuation characteristics of the interplanetary magnetic field throughout the mission, and, where appropriate, relate them to the statics and dynamics of the magnetosphere. The basic instrument of the Magnetic Field Investigation (MFI) is a boom-mounted dual triaxial fluxgate magnetometer and associated electronics. The dual configuration provides redundancy and also permits accurate removal of the dipolar portion of the spacecraft magnetic field. The instrument provides (1) near real-time data at nominally one vector per 92 s as key parameter data for broad dissemination, (2) rapid data at 10.9 vectors s^–1 for standard analysis, and (3) occasionally, snapshot (SS) memory data and Fast Fourier Transform data (FFT), both based on 44 vectors s^–1. These measurements will be precise (0.025%), accurate, ultra-sensitive (0.008 nT/step quantization), and where the sensor noise level is <0.006 nT r.m.s. for 0–10 Hz. The digital processing unit utilizes a 12-bit microprocessor controlled analogue-to-digital converter. The instrument features a very wide dynamic range of measurement capability, from ±4 nT up to ±65 536 nT per axis in eight discrete ranges. (The upper range permits complete testing in the Earth's field.) In the FTT mode power spectral density elements are transmitted to the ground as fast as once every 23 s (high rate), and 2.7 min of SS memory time series data, triggered automatically by pre-set command, requires typically about 5.1 hours for transmission. Standard data products are expected to be the following vector field averages: 0.0227-s (detail data from SS), 0.092 s (detail in standard mode), 3 s, 1 min, and 1 hour, in both GSE and GSM coordinates, as well as the FFT spectral elements. As has been our team's tradition, high instrument reliability is obtained by the use of fully redundant systems and extremely conservative designs. We plan studies of the solar wind: (1) as a collisionless plasma laboratory, at all time scales, macro, meso and micro, but concentrating on the kinetic scale, the highest time resolution of the instrument (=0.022 s), (2) as a consequence of solar energy and mass output, (3) as an external source of plasma that can couple mass, momentum, and energy to the Earth's magnetosphere, and (4) as it is modified as a consequence of its imbedded field interacting with the moon. Since the GEOTAIL Inboard Magnetometer (GIM), which is similar to the MFI instrument, was developed by members of our team, we provide a brief discussion of GIM related science objectives, along with MFI related science goals.  相似文献   

    

Lemme  P.W. Glenister  S.M. Miller  A.W. 《Aerospace and Electronic Systems Magazine, IEEE》1999,14(11):11-16

The ever-increasing demand to stay in touch, to be able to communicate anywhere and anytime, has created a market for low Earth orbit (LEO) satellite communications services such as the Iridium system. The Iridium satellite communications network is being developed to support the needs of the passenger, the cabin crew and the flight crew for: aeronautical public correspondence (APC); aeronautical administrative communications (AAC); aeronautical operational control (AOC); and air traffic services (ATS)  相似文献   

    

Hemant R. Sonawane  Shripad P. Mahulikar   《Aerospace Science and Technology》2011,15(4):249-260

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  总被引：4，自引：0，他引：4  

Betaille  D.F. Cross  P.A. Euler  H.-J. 《IEEE transactions on aerospace and electronic systems》2006,42(2):705-717

The potential of output from a window correlator to mitigate GPS phase multipath is reviewed and assessed based on the analysis of data collected in controlled multipath environments under both static and kinematic conditions. Previous findings that the method is suboptimal for reflectors leading to additional path lengths of less than about 7m are confirmed, and methods for combining this output with two other multipath indicators: time series of signal-to-noise ratios (SNRs) and estimates of code multipath from dual frequency code and phase combinations, are investigated. A new method to combine all three indicators has been found and its application is shown to improve the quality of GPS static phase data by between 10% and 20% depending on the length of the additional path travelled by the reflected signal. The method can be applied completely automatically as it uses just the three multipath indicators; no knowledge of the surrounding environment is required. The paper concludes with some suggested practical applications.  相似文献   

    

M. H. Acuña  D. Curtis  J. L. Scheifele  C. T. Russell  P. Schroeder  A. Szabo  J. G. Luhmann 《Space Science Reviews》2008,136(1-4):203-226

The magnetometer on the STEREO mission is one of the sensors in the IMPACT instrument suite. A single, triaxial, wide-range, low-power and noise fluxgate magnetometer of traditional design—and reduced volume configuration—has been implemented in each spacecraft. The sensors are mounted on the IMPACT telescoping booms at a distance of ～3 m from the spacecraft body to reduce magnetic contamination. The electronics have been designed as an integral part of the IMPACT Data Processing Unit, sharing a common power converter and data/command interfaces. The instruments cover the range ±65,536 nT in two intervals controlled by the IDPU (±512 nT; ±65,536 nT). This very wide range allows operation of the instruments during all phases of the mission, including Earth flybys as well as during spacecraft test and integration in the geomagnetic field. The primary STEREO/IMPACT science objectives addressed by the magnetometer are the study of the interplanetary magnetic field (IMF), its response to solar activity, and its relationship to solar wind structure. The instruments were powered on and the booms deployed on November 1, 2006, seven days after the spacecraft were launched, and are operating nominally. A magnetic cleanliness program was implemented to minimize variable spacecraft fields and to ensure that the static spacecraft-generated magnetic field does not interfere with the measurements.  相似文献   

    

Calvente  J. Martinez-Salamero  L. Garces  P. Romero  A. 《IEEE transactions on aerospace and electronic systems》2003,39(4):1292-1303

A new design technique of the input filter damping network for dc-to-dc switching converters of buck type is presented. This technique is derived by means of zero dynamics analysis of the switching converter and yields equivalent results to those obtained using the classical approach based on minimizing the filter output impedance. The new method can be applied in converters of buck type with two inductors, boost with two inductors and dual SEPIC. Simulation and experimental results corresponding to a boost converter with two inductors illustrate the procedure.  相似文献   

    

Nicosia  S. Tomei  P. 《IEEE transactions on aerospace and electronic systems》1992,28(4):970-977

The problem of controlling a spacecraft by measuring only the angular position (roll, pitch, and yaw) is considered. A nonlinear observer is proposed which asymptotically reconstructs all the spacecraft state variables; if the spacecraft actuators are reaction wheels, the angular velocities of the wheels also must be measured. It is shown that if the observer is used in connection with asymptotically stable state feedback controllers, the extended system (spacecraft, controller, and observer) is still asymptotically stable. Simulation results are reported to illustrate the dynamic behavior of the observer  相似文献   

    

Stern  David P. 《Space Science Reviews》1997,82(3-4):468-468

Space Science Reviews -  相似文献   

    

M. A. Hapgood  T. G. Dimbylow  D. C. Sutcliffe  P. A. Chaizy  P. S. Ferron  P. M. Hill  X. Y. Tiratay 《Space Science Reviews》1997,79(1-2):487-525

The Joint Science Operations Centre (JSOC) has been established to provide the operational interface between the Instrument Principal Investigators (PIs) and the European Space Operations Centre (ESOC). Its key task will be to merge inputs from the Cluster instrument teams and to generate the coordinated command schedule for operation of the scientific payload. In addition, it will collect and process data needed to plan those operations and will monitor the performance of the mission and individual instruments. This paper outlines the JSOC subsystems that have been built to carry out these tasks and highlights points of scientific or technical interest within these systems.  相似文献   

    

R. J. Lillis  D. A. Brain  S. W. Bougher  F. Leblanc  J. G. Luhmann  B. M. Jakosky  R. Modolo  J. Fox  J. Deighan  X. Fang  Y. C. Wang  Y. Lee  C. Dong  Y. Ma  T. Cravens  L. Andersson  S. M. Curry  N. Schneider  M. Combi  I. Stewart  J. Clarke  J. Grebowsky  D. L. Mitchell  R. Yelle  A. F. Nagy  D. Baker  R. P. Lin 《Space Science Reviews》2015,196(1-4):357-358

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