共查询到20条相似文献,搜索用时 31 毫秒
1.
《Aerospace Science and Technology》2000,4(7):507-515
Three collocation strategies are planned and analyzed for the cluster of two geostationary orbit (GEO) satellites and one inclined geosynchronous orbit (GSO) satellite in the same longitude control band of 116°E±0.05° . The longitudinal control bands are allocated for the two GEO satellites and one inclined GSO satellite with seven-day East/West station-keeping maneuver cycle. The latitudinal control bands are allocated for the two GEO satellites with fourteen-day North/South station-keeping maneuver cycle. One inclined GSO satellite is allowed for natural inclination drift. The coordinated eccentricity vector and inclination vector separation method is applied for the collocation, and the maneuver schedule is planned to minimize the operational load by avoiding simultaneous maneuvers. A total of six months of station-keeping maneuver simulations are performed for the three different strategies. 相似文献
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The Lunar Gravity Ranging System for the Gravity Recovery and Interior Laboratory (GRAIL) Mission 总被引:1,自引:0,他引:1
William M. Klipstein Bradford W. Arnold Daphna G. Enzer Alberto A. Ruiz Jeffrey Y. Tien Rabi T. Wang Charles E. Dunn 《Space Science Reviews》2013,178(1):57-76
The Lunar Gravity Ranging System (LGRS) flying on NASA’s Gravity Recovery and Interior Laboratory (GRAIL) mission measures fluctuations in the separation between the two GRAIL orbiters with sensitivity below 0.6 microns/Hz1/2. GRAIL adapts the mission design and instrumentation from the Gravity Recovery and Climate Experiment (GRACE) to a make a precise gravitational map of Earth’s Moon. Phase measurements of Ka-band carrier signals transmitted between spacecraft with line-of-sight separations between 50 km to 225 km provide the primary observable. Measurements of time offsets between the orbiters, frequency calibrations, and precise orbit determination provided by the Global Positioning System on GRACE are replaced by an S-band time-transfer cross link and Deep Space Network Doppler tracking of an X-band radioscience beacon and the spacecraft telecommunications link. Lack of an atmosphere at the Moon allows use of a single-frequency link and elimination of the accelerometer compared to the GRACE instrumentation. This paper describes the implementation, testing and performance of the instrument complement flown on the two GRAIL orbiters. 相似文献
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交会对接任务轨道控制规划设计与实施简 总被引:1,自引:0,他引:1
针对我国空间交会对接轨道控制规划技术,研究了轨道交会优化、应急轨道控制、安全轨道防护和发射窗口规划等一系列关键问题.设计了全寿命周期交会对接任务轨道控制规划方案,从目标飞行器发射到飞船返回,对轨道控制进行了全程协同、全局优化.设计了相位、高度、圆化度多目标融合控制算法;建立了规划变量对远距离导引终点六自由度的独立控制方程;设计了标称整体规划与动态逐级规划相结合的多模式规划策略;基于导引终点整体调整和局部调整的方式,实现了正常和应急条件下天地导引交接点的动态规划;提出了基于飞行控制过程建模的导引终点精度分析方法,确定了地面导引向自主导引切换的关键判据;建立了多约束交会对接发射窗口模型,构建了多任务多年度发射窗口集合.交会对接轨道控制规划技术成功应用于神舟八号、神舟九号和神舟十号交会对接任务. 相似文献
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星间基线高精度确定是分布式干涉合成孔径雷达(InSAR)系统完成科学任务的重要保证,受星载全球定位系统(GPS)接收机连续跟踪弧段短、个别弧段共视GPS卫星个数少或模糊度固定成功率低、频繁轨道机动等因素影响,分布式InSAR高精度基线确定仍有不可靠的风险。通过多机构产品互比来识别基线精度较差的时间段,降低不可靠风险,并通过多机构产品融合进一步提高基线精度。选用重力反演与气候实验(GRACE)卫星数据进行实验,国防科技大学(NDT)和西安测绘研究所(CHS)采用不同的基线处理软件和简化动力学策略,保证了各自的基线产品具有一定的独立性。实验表明,多机构互比对可以有效识别基线精度较差的时间段,NDT和CHS的基线产品之间具有很好的一致性,互比对残差的均方根(RMS)在R、T、N方向分别为0.7、0.9、0.7 mm,二者之间没发现明显系统偏差,大约97.86%的基线三维互比对残差量级在2 mm以内。两个机构基线产品融合后发现可进一步降低基线产品中的随机波动误差,K/Ka波段测距(KBR)系统校核结果表明融合基线产品精度较NDT基线产品提高8.97%,较CHS基线产品提高29.21%。 相似文献
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建立了基于双星定位系统距离和观测数据的近地卫星联合定轨模型,设计了相应的数值融合联合定轨算法;为进一步提高近地卫星定轨精度,考虑融合双星及备份星距离和观测数据,建立了基于双星和备份星的近地卫星联合定轨模型及实现算法,并针对不同仿真条件进行了联合定轨仿真实验。仿真计算结果表明,联合定轨方式较传统近地卫星精密定轨方式可以更好地抑制双星星历误差对近地卫星定轨精度的影响,近地卫星和双星的定轨精度均得到了一定程度的提高;同时,融合备份星观测数据的近地卫星联合定轨精度得到进一步改善,达到5.17m。 相似文献
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《IEEE transactions on aerospace and electronic systems》1993,29(3):910-925
A methodology for the tracking of maneuvering targets is presented. A quickest-detection scheme based on the innovation sequence is developed for a prompt detection of target maneuvers. The optimal length of a sliding window that minimizes the maneuver detection delay for a given false-alarm rate is determined. After maneuver detection, the system model is modified by adding a maneuver term. A recursive algorithm is proposed to estimate the maneuver magnitude. With this estimate, a modified Kalman filter is used for tracking. Simulation results demonstrate the superior performance of the algorithm, especially during target maneuvers 相似文献
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Spaceborne GPS receiver antenna phase center offset and variation estimation for the Shiyan 3 satellite 总被引:3,自引:2,他引:1
《中国航空学报》2016,(5):1335-1344
In determining the orbits of low Earth orbit (LEO) satellites using spaceborne GPS, the errors caused by receiver antenna phase center offset (PCO) and phase center variations (PCVs) are gradually becoming a major limiting factor for continued improvements to accuracy. Shiyan 3, a small satellite mission for space technology experimentation and climate exploration, was developed by China and launched on November 5, 2008. The dual-frequency GPS receiver payload delivers 1 Hz data and provides the basis for precise orbit determination within the range of a few centime-ters. The antenna PCO and PCV error characteristics and the principles influencing orbit determi-nation are analyzed. The feasibility of PCO and PCV estimation and compensation in different directions is demonstrated through simulation and in-flight tests. The values of receiver antenna PCO and PCVs for Gravity Recovery and Climate Experiment (GRACE) and Shiyan 3 satellites are estimated from one month of data. A large and stable antenna PCO error, reaching up to 10.34 cm in the z-direction, is found with the Shiyan 3 satellite. The PCVs on the Shiyan 3 satellite are estimated and reach up to 3.0 cm, which is slightly larger than that of GRACE satellites. Orbit validation clearly improved with independent k-band ranging (KBR) and satellite laser ranging (SLR) measurements. For GRACE satellites, the average root mean square (RMS) of KBR resid-uals improved from 1.01 cm to 0.88 cm. For the Shiyan 3 satellite, the average RMS of SLR resid-uals improved from 4.95 cm to 4.06 cm. 相似文献
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James V. McAdams Robert W. Farquhar Anthony H. Taylor Bobby G. Williams 《Space Science Reviews》2007,131(1-4):219-246
Nearly three decades after the Mariner 10 spacecraft’s third and final targeted Mercury flyby, the 3 August 2004 launch of
the MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) spacecraft began a new phase of exploration
of the closest planet to our Sun. In order to ensure that the spacecraft had sufficient time for pre-launch testing, the NASA
Discovery Program mission to orbit Mercury experienced launch delays that required utilization of the most complex of three
possible mission profiles in 2004. During the 7.6-year mission, the spacecraft’s trajectory will include six planetary flybys
(including three of Mercury between January 2008 and September 2009), dozens of trajectory-correction maneuvers (TCMs), and
a year in orbit around Mercury. Members of the mission design and navigation teams optimize the spacecraft’s trajectory, specify
TCM requirements, and predict and reconstruct the spacecraft’s orbit. These primary mission design and navigation responsibilities
are closely coordinated with spacecraft design limitations, operational constraints, availability of ground-based tracking
stations, and science objectives. A few days after the spacecraft enters Mercury orbit in mid-March 2011, the orbit will have
an 80° inclination relative to Mercury’s equator, a 200-km minimum altitude over 60°N latitude, and a 12-hour period. In order
to accommodate science goals that require long durations during Mercury orbit without trajectory adjustments, pairs of orbit-correction
maneuvers are scheduled every 88 days (once per Mercury year). 相似文献
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某地球同步三轴卫星因故障导致推力器工作效率不稳定,使得采用原有方案进行向西轨道控制时姿态变化大,控制准确度降低.针对上述问题,通过分析卫星用于姿态控制的偏置动量轮的控制规律,利用星体角动量守恒条件,建立了偏置动量轮转速变化与轨道半长轴变化之间的相关性数学模型,提出了一种改进的基于偏置动量轮转速标定的轨道控制方法,同时结合姿态的稳定变化制定了轨道控制实施方案,并将其应用于实际卫星轨道控制中,取得了良好的控制效果.改进的控制方法提高了轨道控制的准确率,使得半长轴误差幅度由最大60%提高到0.2%左右,增加了姿态的稳定性,使得俯仰姿态变化幅度由最大0.7°减小到0.2°左右,降低了控制风险,减轻了地面控制人员的负担. 相似文献
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Possible Future Use of Laser Gravity Gradiometers 总被引:1,自引:0,他引:1
With the GRACE mission under way and the GOCE mission well along in the design process, detailed questions concerning the
type of future mission that may follow them have arisen. It is generally agreed that determining the time variations in the
Earth's gravity field with as high spatial and temporal resolution as is feasible will be the main driver for such a mission.
The possible use of laser heterodyne measurements between separate satellites in such a mission has been discussed by a number
of people. The first suggestion of emphasizing time variation measurements in a laser mission was the TIDES concept presented
in 1992 by Colombo and Chao. Then, in 2000, a GRACE Follow-On mission using laser measurements between two drag-free satellites
was discussed by Watkins el al. (2000).
More recently, the possibility of utilizing laser measurements between more than two satellites in order to determine two
or more components of the gravity gradient tensor simultaneously has been proposed by Balmino. This approach may be desirable
in order to reduce the aliasing of time variations between geopotential terms of different degree and order, as well as to
improve the resolution in longitude, despite the cost of the additional satellites. In this paper, we discuss specific possible
mission geometries for measuring the two diagonal in-plane components of the gravity gradient tensor simultaneously. This
could be done, for example, by laser heterodyne measurements between two pairs of satellites in coplanar and nearly polar
orbits.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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B. Williams P. Antreasian E. Carranza C. Jackman J. Leonard D. Nelson B. Page D. Stanbridge D. Wibben K. Williams M. Moreau K. Berry K. Getzandanner A. Liounis A. Mashiku D. Highsmith B. Sutter D. S. Lauretta 《Space Science Reviews》2018,214(4):69
OSIRIS-REx is the first NASA mission to return a sample of an asteroid to Earth. Navigation and flight dynamics for the mission to acquire and return a sample of asteroid 101955 Bennu establish many firsts for space exploration. These include relatively small orbital maneuvers that are precise to ~1 mm/s, close-up operations in a captured orbit about an asteroid that is small in size and mass, and planning and orbit phasing to revisit the same spot on Bennu in similar lighting conditions. After preliminary surveys and close approach flyovers of Bennu, the sample site will be scientifically characterized and selected. A robotic shock-absorbing arm with an attached sample collection head mounted on the main spacecraft bus acquires the sample, requiring navigation to Bennu’s surface. A touch-and-go sample acquisition maneuver will result in the retrieval of at least 60 grams of regolith, and up to several kilograms. The flight activity concludes with a return cruise to Earth and delivery of the sample return capsule (SRC) for landing and sample recovery at the Utah Test and Training Range (UTTR). 相似文献
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《Aerospace Science and Technology》2000,4(3):215-221
The orbit determination using the GPS navigation solutions for the KOMPSAT-1 spacecraft has been studied. The Cowell method of special perturbation theories was employed to develop a precision orbit propagation, and the perturbations due to geopotential, the gravity of the Sun and the Moon, solid Earth tides, ocean tides, the Earth's dynamic polar motion, solar radiation pressure, and atmospheric drag were modeled. Specifically, the satellite box-wing macro model was applied to minimize the drag errors at low altitude. The estimation scheme consisted of an extended Kalman filter and Bayesian least square method. To investigate the applicability of the method to the KOMPSAT-1 spacecraft, the orbit determination was accomplished using the GPS navigation solutions for the TOPEX/POSEIDON and TAOS satellites. The orbit determination results were compared with NASA POE generated by global laser tracking. The position and velocity accuracy was estimated about 16∼7 m and 0.0157∼0.0074 m·s−1 RMS, respectively, for the two satellites in the presence of SA. These results verify that an orbit determination scheme using GPS navigation solutions can provide the static orbit information and reduce conspicuously the position and velocity errors of navigation solutions. It can be suggested that the sequential and batch orbit determination using the GPS navigation solutions be the most appropriate method in the KOMPSAT-1 type mission. 相似文献
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Classical bearings-only target-motion analysis (TMA) is restricted to sources with constant motion parameters (usually position and velocity). However, most interesting sources have maneuvering abilities, thus degrading the performance of classical TMA. In the passive sonar context a long-time source-observer encounter is realistic, so the source maneuver possibilities may be important in regard to the source and array baseline. This advocates for the consideration and modeling of the whole source trajectory including source maneuver uncertainty. With that aim, a convenient framework is the hidden Markov model (HMM). A basic idea consists of a two-levels discretization of the state-space. The probabilities of position transition are deduced from the probabilities of velocity transitions which, themselves, are directly related to the source maneuvering capability. The source state sequence estimation is achieved by means of classical dynamic programming (DP). This approach does not require any prior information relative to the source maneuvers. However, the probabilistic nature of the source trajectory confers a major role to the optimization of the observer maneuvers. This problem is then solved by using the general framework of the Markov decision process (MDP) 相似文献
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In this paper some basic concepts involved in efficient orbit/spectrum utilization for broadcast satellites are discussed. A theoretical analysis leads to the determination of interference zones and minimum number of frequency channels required for homogeneous systems operating in the 800-MHz and 12-GHz bands. A crossed-beam arrangement of satellite systems is proposed, in which the beams from satellites to service areas cross each other. This arrangement has a more efficient orbit spectrum utilization compared to the identical-longitude approach, in which the subsatellite point has the same longitude as the center of the service area, Based upon practical considerations, the elemental number of frequency channels required for world-wide coverage has been calculated in relation to satellite orbital position, for single-beam and multibeam satellite systems, using the identical-longitude and crossed -beam arrangements. 相似文献
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Robot-aided remote inspection experiment on STS-85 总被引:1,自引:0,他引:1
Kimura S. Okyuama T. Yoshioka N. Wakabayashi Y. 《IEEE transactions on aerospace and electronic systems》2000,36(4):1290-1297
The results are presented for the robot-aided spacecraft inspection experiments using a flaw detection algorithm called multi-images overcast (MIO), which were conducted as an extension of NASDA's Manipulator Flight Demonstration mission installed on space shuttle mission STS-85. These experiments are the first step towards research and development of the Orbital Maintenance System to support space systems by inspecting satellites, deorbiting useless satellites, and repairing satellites in orbit to utilize space systems effectively and reliably. 相似文献