共查询到19条相似文献,搜索用时 125 毫秒
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“风云二号”自旋稳定地球同步气象卫星,以地球脉冲作为姿态控制基准,以太阳脉冲作为图像扫描基准,太阳、地球、卫星三者之间的相对关系在连续不断地运动变化。为了验证扫描成像原理和在地面测试卫星的成像质量,需对三者的相对关系进行研究。在此基础上,研制出太阳、地球、卫星相关模拟源,成功地用电子信号准确模拟“风云二号”卫星在静止轨道上感受到的不断变化的太阳、地球信号,使卫星的成像测试顺利进行,同时发现了卫星设计中存在的问题。 相似文献
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中国-巴西地球资源卫星及其应用前景 总被引:5,自引:0,他引:5
1999年10月14日,我国使用长征4号乙火箭发射了我国和巴西共同研制的第一颗地球资源卫星(CBERS)。这是中国和巴西两个发展中国家在空间技术领域的第一个合作计划。现将有关情况介绍如下:一、中国巴西地球资源卫星的基本特征 卫星系统性能特点1卫星的轨道是太阳同步回归?.. 相似文献
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中国巴西地球资源卫星的轨道捕获和轨迹交会控制 总被引:2,自引:1,他引:2
中巴地球资源卫星一号(CBERS-1)是中国和巴西合作研制的第一颗运行在太阳同步轨道上的地球资源卫星.CBERS-1于1999年10月14日由中国自行研制的长征运载工具按预定计划准时发射,进入设计轨道,随后通过轨道捕获、星下点轨迹控制和多次轨道保持机动等一系列轨道测控操作,该卫星已按遥感用户的要求正常运行在高精度的太阳同步、回归冻结轨道上.本文简要阐明CBERS-1轨道控制系统的任务目标、系统结构、轨道控制策略、控制性能、飞行软件和在轨操作以及飞行结果. 相似文献
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20世纪90年代末开始的重返月球的航天活动中,已实现的和将要实现的飞行任务中,绝大部分都属于月球遥感。地球遥感卫星大部分采用太阳同步、回归轨道,有的还采用冻结轨道,因为这些轨道特性对卫星遥感是非常有利的。那么月球遥感卫星是否具有同样特性的轨道?这是该文回答的问题。 相似文献
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地球静止轨道卫星寿命末期离轨方案研究 总被引:1,自引:0,他引:1
文章对于寿命末期的地球静止轨道卫星根据弃星轨道高度的计算公式(ΔH≥235 1000C_rA/M)计算了卫星寿命末期离轨的燃料需求,对化学推进和电推进两种离轨方案进行了比较,并详细叙述了卫星离轨后必要的钝化措施。 相似文献
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采用自主导航技术,可以降低月球卫星的任务成本,提高其生存能力。现研究了利用太阳敏感器、地球敏感器和月球敏感器测量出的卫星-太阳、卫星-地球和卫星-月球方向矢量作为观测量,采用迭代最小二乘方法、定历元时刻的卫星状态,并以轨道预报的方式实现月球卫星的自主导航。对该自主导航算法进行了数学仿真,分析比较了敏感器精度、部分轨道参数等因素对定位精度的影响,总结了其变化规律。最后对比了迭代最小二乘方法与扩展卡尔曼滤波的导航仿真结果,结果表明前者具有更高的精度。 相似文献
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地球轨道卫星电推进变轨控制方法 总被引:1,自引:0,他引:1
针对地球同步轨道(GEO)卫星,采用电推进系统完成转移轨道变轨。采用基于Lyapunov函数的反馈控制方法确定时间最短变轨策略。首先在开普勒模型下研究变轨过程,然后在开普勒模型的基础上考虑地球J2项摄动和地球阴影,最后在全引力模型下研究变轨过程,即在开普勒模型的基础上考虑地球非球形引力摄动、日月第三体引力摄动、太阳光压摄动和地球阴影。仿真结果显示在变轨过程中摄动项不可忽略,除地球J2项摄动外还应该考虑日月第三体引力摄动和太阳光压摄动。对比上述三组仿真结果,发现考虑摄动后轨道转移时间的增加比燃料消耗的增加更为明显。数值仿真结果表明本文研究对未来的全电推进任务具有良好的通用性和应用参考价值。 相似文献
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First order averaging is applied to the artificial satellite problem to obtain the averaged orbit which includes the secular, long and medium period effects of the oblateness of the Earth and the third body perturbations of the moon and sun. Perturbation theory is then used to recover the short period effects due to J2, the moon, and sun. The perturbation analysis is carried out by means of Lie series and is developed through the first order. Optimization of the resulting short period series was then accomplished in several steps: first all separate algebraic coefficients were precalculated and stored; then all redundant SIN/COS calls were eliminated; next all repetition of numeric and algebraic coefficients were precalculated in pairs; application of the distributive principle allowed a significant reduction in additions and multiplications; finally trigonometric identities were used to further reduce the SIN/COS computations. The result of this optimization along with an interpolator for the averaged equations of motion results in a computer program which requires only the CPU time (with no loss in accuracy) of the original non-optimized test program. 相似文献
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相对轨道自主确定方法的改进 总被引:4,自引:1,他引:3
编队飞行卫星相对轨道的确定具有重要意义。本文提出一种完全自主的定轨方案,在利用星间测量信息实现编队飞行卫星自主定轨的基础上,引入太阳敏感器测量信息,利用扩展卡尔曼滤波算法提高环绕星相对轨道确定精度。仿真结果验证了这种导航方案和算法的有效性。 相似文献
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《中国航天(英文版)》2019,(3)
Queqiao relay communications satellite was developed to provide relay communications services for the lander and the rover on the far side of the moon. From entering into its halo mission orbit around the Earth-moon libration point 2 on June 14, 2018, it has operated on orbit more than fifteen months. It worked very well and provided reliable, continuous relay communications services for the lander and the rover to accomplish the goals of Chang'e 4 lunar far side soft landing and patrol exploration mission. The on-orbit operation status of Queqiao relay communications satellite is summarized in this paper. 相似文献
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《中国航天(英文版)》2019,(2)
The far side of the moon is a unique place for some scientific investigations. Chang'e 4 is a Chinese lunar far side landing exploration mission. Relay communication satellite, named as Queqiao, is an important and innovative part of Chang'e 4 mission. It can provide relay communication to the lander and the rover operating on the lunar far side to maintain their contacts with Earth. It was launched by LM-4 C launch vehicle at the Xichang Satellite Launch Center on May 21, 2018. After five precise orbit controls and a journey of more than 20 days, Queqiao inserted into final halo mission orbit around Earth-moon libration point 2, located about 65,000 km beyond the moon. It is the world's first communication satellite operating in that orbit. Up to now, Queqiao worked very well and provided reliable, continuous communication relay service for the lander and the rover to ensure the mission success of Chang'e 4 exploration mission. Via Queqiao, the lander and the rover were controlled to work by ground stations and obtained a great amount of scientific data. The mission overview, operation orbit selection, relay communication system design and flight profile were introduced in this article. 相似文献