共查询到19条相似文献,搜索用时 140 毫秒
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即使静止、同步卫星有着标称位置,但由于各种摄动的存在会使卫星轨道发生漂移.而在许多应用中,例如高精度时间同步,必须精确知道卫星的轨道.另外,由于很少为时间传递、时间同步发射专用卫星,所以它通常使用以其他目的为基本任务的卫星,如气象卫星、通信广播卫星等.以往,这些卫星的轨道信息总是由卫星主管部门给出,在这种情况下,卫星的轨道确定不可能专门考虑第二目的.为此,应用部门为了满足自己的需要,在不影响卫星基本功能条件下,采用闭路动态技术来精确确定卫星的轨道.本文在简要叙述闭路动态卫星定轨原理的基础上,探讨了利用卫星彩色电视副载波信号测速进行同步卫星定轨的可能性.并给出单台站的某些试验测量结果. 相似文献
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不同导航系统中卫星的形状、材料、轨道设计和姿态控制模式等都不相同,在进行多系统数据联合处理时,要获得高精度的卫星轨道,需要区别对待不同类型卫星的姿态模型和光压模型。作为导航卫星所受量级最大的非保守力,国内外许多研究是围绕光压模型的建立与精化等方面来开展,以便建立最合适的模型,从而获取更高的定轨精度。目前的研究表明,新的Galileo以及北斗卫星采用与之前不同的姿态控制模式,适用的光压模型也不同。总结了目前比较通用的导航卫星姿态模型,尤其是官方最新公布的北斗卫星的姿态模型,详细介绍了卫星光压模型研究进展和近几年来新发射卫星光压模型以及其先验模型的构建方法,并分析了各个模型的优缺点和适应性。通过对目前导航卫星姿态以及光压模型的分析,提出在更高精度的定轨任务中有待改进的问题,为导航卫星尤其是新发射导航卫星精密定轨中的光压和姿态模型的选择和建立提供参考。 相似文献
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漂移扫描CCD用于地球同步轨道卫星观测的初步结果 总被引:1,自引:0,他引:1
对于地球同步轨道卫星,目前国内主要采用两种观测手段,即小光电望远镜短曝光观测和天文望远镜跟踪恒星(或卫星)观测.事实上,这两种手段都各自存在不足,尤其对于暗弱目标问题更加显著.利用CCD漂移扫描模式和凝视模式相结合观测地球同步轨道卫星具有明显的优势,小口径望远镜(口径约25cm)就能够获得高质量的目标和恒星圆星像与高精度的定位结果.本文重点阐述了获得高精度地球同步轨道卫星光学位置与星等的原理、方法及步骤;最后,利用实测资料的数据处理结果,分析了所获得的地球同步轨道卫星的内部精度及其误差源. 相似文献
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由于星际探测事业的发展,对土星卫星的定位精度要求愈来愈高,经典的分析法定轨方法已难以适应,在当今计算技术条件高度发展的背景下,本文给出了土星卫星的数值法定轨方案,采用了土星卫星运动的高精度力学模型,并运用1874-1989这100多年间的观测资料,引用现代最小二乘估计,对土星卫生进行精密定轨。该方案可以在引用同样的力学模型的前提下,对土星各颗卫星进行定轨,亦可同时进行多颗卫星的定轨。相应的软件比较 相似文献
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DORIS系统及其结果 总被引:1,自引:0,他引:1
蒋达西 《紫金山天文台台刊》1994,13(1):40-46
本文阐述了DORIS系统,它是目前一种新型的高精度的测轨定位系统跟踪网,介绍了它近几年来进展过程和今后的发展前景.DORIS系统为低轨道卫星的测轨精度约为10cm.根据以往DORIS资料的估算结果,它可提供低于10m的绝对定位和几个厘米的相对定位精度。 相似文献
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针对地基卫星测控系统(Tracking Telemetry and Command, TT&C)系统对地球静止轨道(Geostation-\lk ary Earth Orbit, GEO)卫星在空间和时间覆盖上的局限性, 提出小倾角低地球轨道(Low Earth Orbit, LEO)多星组网天基平台对GEO卫星进行跟踪定轨的方法. 根据空间环境和光学可视条件对仿真数据进行筛选以模拟真实的观测场景, 利用光学测角数据, 使用数值方法对GEO卫星的轨道进行确定. 结果与参考轨道进行重叠对比, 在平台轨道精度5 m、测量精度5rq\rq、 定轨弧长12 h的情况下, 两颗LEO卫星对GEO卫星进行跟踪定轨的精度可达到千米量级, 4颗LEO卫星对GEO目标进行跟踪定轨的精度可达到百米量级. 随着LEO组网卫星数量的增加, 定轨精度得到了较大的提高. 相似文献
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月球卫星轨道力学综述 总被引:5,自引:0,他引:5
月球探测器的运动通常可分为3个阶段,这3个阶段分别对应3种不同类型的轨道:近地停泊轨道、向月飞行的过渡轨道与环月飞行的月球卫星轨道。近地停泊轨道实为一种地球卫星轨道;过渡轨道则涉及不同的过渡方式(大推力或小推力等);环月飞行的月球卫星轨道则与地球卫星轨道有很多不同之处,它决不是地球卫星轨道的简单克隆。针对这一点,全面阐述月球卫星的轨道力学问题,特别是环月飞行中的一些热点问题,如轨道摄动解的构造、近月点高度的下降及其涉及的卫星轨道寿命、各种特殊卫星(如太阳同步卫星和冻结轨道卫星等)的轨道特征、月球卫星定轨等。 相似文献
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LAGEOS卫星精密定轨及残差分析 总被引:6,自引:2,他引:6
介绍LAGEOS卫星用卫星激光测距(SLR)资料精密定轨和在精密定轨基础上的残差分析处理.SLR资料的分析处理方法、采用的力学模型和解参数的多少根据目标的不同而不同.对不同的方案进行了详细分析、比较.其关键是对LAGEOS卫星进行精密定轨.得出了目前上海天文台在SLR资料的分析处理中已采用的解算模式.作为例证,该解算模式分析处理了1998年12月31日至1999年6月29日LAGEOS卫星的SLR资料,得到每3天一个弧段的精密轨道.结果显示每3天一个弧段的定轨残差rms都小于2厘米.上海天文台从1999年10月1日开始了全球LAGEOS—l和LAGEOS—2资料的快速分析服务,结果可从APSG的网址:http://center.shao.ac.cn/APSG/result获得. 相似文献
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The smallness parameter of the approximation method is defined in terms of the non-dimensional initial distance between target and chaser satellite. In the case of a circular target orbit, compact analytical expressions are obtained for the interception travel time up to third order. For eccentric target orbits, an explicit result is worked out to first order, and the tools are prepared for numerical evaluation of higher order contributions. The possible transfer orbits are examined within Lambert’s theorem. For an eventual rendezvous it is assumed that the directions of the angular momenta of the two orbits enclose an acute angle. This assumption, together with the property that the travel time should vanish with vanishing initial distance, leads to a condition on the admissible initial positions of the chaser satellite. The condition is worked out explicitly in the general case of an eccentric target orbit and a non-coplanar transfer orbit. The condition is local. However, since during a rendezvous maneuver, the chaser eventually passes through the local space, the condition propagates to non-local initial distances. As to quantitative accuracy, the third order approximation reproduces the elements of Mars, in the historical problem treated by Gauss, to seven decimals accuracy, and in the case of the International Space Station, the method predicts an encounter error of about 12 m for an initial distance of 70 km. 相似文献
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Diana W. Scott 《Planetary and Space Science》1967,15(12):1895-1911
An Earth satellite can only be observed by optical methods when it is illuminated by sunlight and the observing station is in darkness, with the result that the satellite is in general only visible on two fairly small arcs of its orbit.
In this paper, a graphical method has been developed for predicting the latitudes from which a satellite in a circular orbit is visible, with the particular aim of discovering periods when a satellite may be observed in mid-latitudes in both the northern and southern hemispheres. For near-polar orbits the occurrence of such periods depends critically on the position of the ascending node of the orbit; but for lower inclinations, the periods of visibility become shorter and more frequent, and the orientation of the orbit is less significant. 相似文献
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SONG Ye-zhi HUANG Yong HU Xiao-gong LI Pei-jia CAO Jian-feng 《Chinese Astronomy and Astrophysics》2014
It is known that the dynamical orbit determination is the most common way to get the precise orbits of spacecraft. However, it is hard to build up the precise dynamical model of spacecraft sometimes. In order to solve this problem, the technique of the orbit determination with the B-spline approximation method based on the theory of function approximation is presented in this article. In order to verify the effectiveness of this method, simulative orbit determinations in the cases of LEO (Low Earth Orbit), MEO (Medium Earth Orbit), and HEO (Highly Eccentric Orbit) satellites are performed, and it is shown that this method has a reliable accuracy and stable solution. The approach can be performed in both the conventional celestial coordinate system and the conventional terrestrial coordinate system. The spacecraft's position and velocity can be calculated directly with the B-spline approximation method, it needs not to integrate the dynamical equations, nor to calculate the state transfer matrix, thus the burden of calculations in the orbit determination is reduced substantially relative to the dynamical orbit determination method. The technique not only has a certain theoretical significance, but also can serve as a conventional algorithm in the spacecraft orbit determination. 相似文献
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W.J. Boulton 《Planetary and Space Science》1984,32(3):287-296
The effect of solar radiation pressure on the orbits of cylindrical satellites is considered. The cylinder is assumed to reflect radiation both specularly and diffusely. The resultant forces on a stationary cylindrical satellite are given. The evolution of the satellite's orbit is described for two particular modes of rotation. In both cases the satellites are assumed to be in circular Sun-synchronous orbits. 相似文献
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Yu Cheng Gerard Gómez Josep J. Masdemont Jianping Yuan 《Celestial Mechanics and Dynamical Astronomy》2017,128(4):409-433
This paper is devoted to the study of the transfer problem from a libration point orbit of the Earth–Moon system to an orbit around the Moon. The transfer procedure analysed has two legs: the first one is an orbit of the unstable manifold of the libration orbit and the second one is a transfer orbit between a certain point on the manifold and the final lunar orbit. There are only two manoeuvres involved in the method and they are applied at the beginning and at the end of the second leg. Although the numerical results given in this paper correspond to transfers between halo orbits around the \(L_1\) point (of several amplitudes) and lunar polar orbits with altitudes varying between 100 and 500 km, the procedure we develop can be applied to any kind of lunar orbits, libration orbits around the \(L_1\) or \(L_2\) points of the Earth–Moon system, or to other similar cases with different values of the mass ratio. 相似文献
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By sending one or more telescopes into space,Space-VLBI(SVLBI)is able to achieve even higher angular resolution and is therefore the trend of the VLBI technique.For the SVLBI program,the design of satellite orbits plays an important role for the success of planned observation.In this paper,we present our orbit optimization scheme,so as to facilitate the design of satellite orbits for SVLBI observation.To achieve that,we characterize the uv coverage with a measure index and minimize it by finding out the corresponding orbit configuration.In this way,the design of satellite orbit is converted to an optimization problem.We can prove that,with an appropriate global minimization method,the best orbit configuration can be found within the reasonable time.Besides that,we demonstrate that this scheme can be used for the scheduling of SVLBI observations. 相似文献