共查询到20条相似文献,搜索用时 921 毫秒
1.
2.
SGP4/SDP4模型精度分析 总被引:2,自引:0,他引:2
本文基于最新发布的SGP4/SDP4(Simplified General Perturbation Version 4/Simplified Deep-space Perturbation Version 4)模型设计了一套定轨方案,从空间目标库中挑选出不同类型和轨道参数的1120个目标进行计算,定量给出了SGP4/SDP4模型处理不同类型空间目标的定轨预报精度.结果表明:近地目标定轨精度为百米量级;半同步和同步轨道定轨精度平均为0.7和1.9km.椭圆轨道目标的定轨精度与偏心率有关,除少数e>0.8的椭圆轨道目标,绝大多数椭圆轨道目标定轨误差均小于10km.用SGP4/SDP4模型对近地目标预报3天,半同步轨道预报30天,同步轨道预报15天,椭圆轨道预报1天,预报误差一般不超过40km. 相似文献
3.
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
4.
Walter Petry 《Astrophysics and Space Science》1995,232(2):233-240
The previously studied 2-post-Newtonian approximation of the gravitational field of a nonstationary spherically symmetric star in flat space-time theory of gravitation is applied to the motion of a test particle in the orbit of the star. The orbit is different from the one of Einstein's general theory of relativity. A general formula for the deviation of the orbit from a circle is given. In the special case of a radially oscillating star, being homogeneous to Newtonian accuracy, the orbit of the test particle also oscillates radially with small amplitude about a fixed orbit (circle). 相似文献
5.
连线干涉测量(Connected Element Interferometry, CEI)是一种全天时全天候的被动测角技术, 已用于空间目标的跟踪监视. 地球静止轨道(Geostationary Earth Orbit, GEO)卫星需要频繁机动以保持轨位或完成其他任务, 其机动后的快速轨道恢复能力对于监视预警极为重要. 针对基于CEI的GEO短弧定轨和预报, 分析了定轨算法的形亏和数亏, 在附加先验轨道约束的短弧定轨基础上, 提出了轨道半长轴初值的自适应优化方法. 利用亚太七号卫星的CEI仿真和实测数据进行了短弧定轨和预报, 实验结果表明, 采用优化后的半长轴初值, 30min短弧定轨和10min预报的卫星位置分量精度均优于4km, 能够满足非合作GEO目标机动后快速轨道恢复的需求. 相似文献
6.
Martin Connors Christian Veillet Ramon Brasser Paul Wiegert Paul Chodas Seppo Mikkola Kimmo Innanen 《Meteoritics & planetary science》2004,39(8):1251-1255
Abstract— The newly discovered asteroid 2003 YN107 is currently a quasi‐satellite of the Earth, making a satellite‐like orbit of high inclination with apparent period of one year. The term quasi‐satellite is used since these large orbits are not completely closed, but rather perturbed portions of the asteroid's orbit around the Sun. Due to its extremely Earth‐like orbit, this asteroid is influenced by Earth's gravity to remain within 0.1 AU of the Earth for approximately 10 years (1997 to 2006). Prior to this, it had been on a horseshoe orbit closely following Earth's orbit for several hundred years. It will re‐enter such an orbit, and make one final libration of 123 years, after which it will have a close interaction with the Earth and transition to a circulating orbit. Chaotic effects limit our ability to determine the origin or fate of this object. 相似文献
7.
太阳同步卫星的控制现状及发展趋势 总被引:1,自引:0,他引:1
在介绍太阳同步轨道相关知识的基础上,着重分析了该轨道的高度因素,给出了当前在轨太阳同步卫星轨道高度的上下限,介绍了几种典型的低轨道太阳同步卫星,同时给出了太阳同步卫星轨道控制方法的发展状况及趋势,最后综述了当前国内外太阳同步轨道的轨控模式与维持策略。 相似文献
8.
对于改进的Encke方法,选择适当的参考轨道是一个关键.然而,对于人造地球卫星长弧轨道计算,目前所给出的几种参考轨道均需要逐段校正,这将给定轨问题带来附加的复杂性.本文将仔细探讨如何选择参考轨道和减少校正次数. 相似文献
9.
通过模拟长达100天的星载GPS伪距观测资料,进行卡尔曼滤波定轨仿真计算.重点研究:1)采用简化的动力学模型与简化状态转移矩阵,是否保证滤波的长期稳定性;2)模型误差矩阵Q的选取对滤波定轨精度的影响;3)与事后最小二乘批处理相比较,在简化模型下自主定轨的精度.同时给出了相应的结论. 相似文献
10.
Gang Zhang Di Zhou Zhaowei Sun Xibin Cao 《Celestial Mechanics and Dynamical Astronomy》2013,117(2):137-148
The problem of two-body linearized periodic relative orbits with eccentric reference orbits is studied in this paper. The periodic relative orbit in the target-orbital coordinate system can be used in fly-around and formation-flying orbit design. Based on the closed-form solutions to the Tschauner–Hempel equations, the initial condition for periodic relative orbits is obtained. Then the minimum-fuel periodic-orbit condition with a single impulse is analytically derived for given initial position and velocity vectors. When considering the initial coasting time, the impulse position of the global minimum-fuel periodic orbit is proved to be near to the perigee of the target and can be obtained by numerical optimization algorithms. Moreover, the condition for a special periodic orbit, i.e., the rectilinear relative orbit in the target-orbital frame, is obtained. Numerical simulations are used to demonstrate the efficacy of the method, and show the geometry of the periodic relative orbit and the rectilinear relative orbit. 相似文献
11.
The satellite-borne GPS receivers dedicated to precise orbit determination are now being carried by more and more low earth orbit (LEO) satellites and the satellite-borne GPS has become one of the main means for the precise orbit determination of low earth orbit satellites. The accuracy of satellite-borne GPS precise orbit determination depends on the accuracies of the GPS ephemeris and the clock error. Based on the orbit determination function of SHORDEIII zero-difference dynamics and using the observational data obtained by the GRACE satellites for the week from 2005 August 1 to 7 as an example, three versions of GPS ephemerides (igs, igr and igu) are used to carry out orbit determination under the same conditions and to estimate the effect of the GPS ephemeris accuracy on the accuracy of orbit determination of low earth orbit satellites. Our calculated results show that the two ephemerides, igs and igr, are equivalent to each other in orbit determination accuracy (about 9.5 cm), while igu is slightly less accurate, at about 10.5 cm. The effect produced by the data of the high frequency GPS satellite clock error on the accuracy of orbit determination is 1–6 cm. 相似文献
12.
13.
14.
A method of realtime autonomous orbit determination for earth satellites using the extended Kalman filtering is proposed. The observed quantities are: the satellite-sun direction vector measured by a sun sensor, the satellite-earth and satellite-moon direction vectors measured by an ultraviolet sensor, and the geocentric distance measured by a radar altimeter. At the same time the satellite attitude to the earth is also determined. Results of our simulation of the autonomous orbit determination show that the precision of the orbit determinations is better than 200 m. The effects of the sampling period, orbital inclination, orbital eccentricity and orbital altitude on the precision of orbit determination are analyzed and compared, and certain principles helpful for improving the precision of orbit determination are suggested. 相似文献
15.
抗差估计在星载GPS卫星非差运动学定轨中的应用 总被引:1,自引:0,他引:1
针对星载GPS卫星非差运动学定轨的特点,提出将抗差估计应用于星载GPS卫星运动学定轨,一方面尽量保留来自每颗GPS卫星的观测值,保持较强的卫星几何强度,避免轨道求解出现奇异;另一方面,采用等价权思想,有效地降低质量较差的观测值对定轨结果的影响,保证定轨精度.还采用CHAMP卫星的实测GPS数据验证了新方案的可行性和有效性. 相似文献
16.
17.
IWAN P. WILLIAMS G. O. RYABOVA A. P. BATURIN A. M. CHERNITSOV 《Earth, Moon, and Planets》2004,95(1-4):11-18
The orbit of asteroid 2003 EH1 is very similar to the mean orbit of the Quadrantid meteoroid stream so that a close relationship
between the two is very likely. It has already been suggested that Comet C/1490 Y1 could be the parent of the Quadrantids.
If this is the case, then some relationship between the comet and the asteroid might be expected. The orbit of C/1490 Y1 is
based on a short observing arc of about 6 weeks and all the observations were with the naked eye, so that its elements are
very poorly determined. Hence, forward integration to determine whether asteroid 2003 EH1 represents the re-discovery of the
dormant nucleus of C/1490 Y1 is not feasible. Instead we choose to integrate back in time the orbit of 2003 EH1, which is
far better determined, and a family of 3500 clones, all of which are moving on an orbit that is consistent with the present
known orbit of 2003EH1. We compare the results primarily with the recorded observations of the comet rather than the orbit
of the comet derived by Hasegawa. We find that one clone is consistent with these observations. 相似文献
18.
19.
Generally, any initially-close satellites—chief and deputy—moving on orbits with slightly different orbital elements, will depart each other on locally unbounded relative trajectories. Thus, constraints on the initial conditions must be imposed to mitigate the chief-deputy mutual departure. In this paper, it is analytically proven that choosing the chief’s orbit to be a frozen orbit can mitigate the natural relative drift of the satellites. Using mean orbital element variations, it is proven that if the chief’s orbit is frozen, then the mean differential eccentricity is periodic, leading to a periodic variation of the differential mean argument of latitude. On the other hand, if the chief’s orbit is non-frozen, a secular growth in the differential mean argument of latitude leads to a concomitant along-track separation of the deputy from the chief, thereby considerably increasing the relative distance evolution over time. Long-term orbital simulation results indicate that the effect of choosing a frozen orbit vis-à-vis a non-frozen orbit can reduce the relative distance drift by hundreds of meters per day. 相似文献
20.
With the increase in complexities of interplanetary missions, the main focus has shifted to reducing the total delta-V for the entire mission and hence increasing the payload capacity of the spacecraft. This paper develops a trajectory to Mars using the Lagrangian points of the Sun-Earth system and the Sun-Mars system. The whole trajectory can be broadly divided into three stages: (1) Trajectory from a near-Earth circular parking orbit to a halo orbit around Sun-Earth Lagrangian point L2. (2) Trajectory from Sun-Earth L2 halo orbit to Sun-Mars L1 halo orbit. (3) Sun-Mars L1 halo orbit to a circular orbit around Mars. The stable and unstable manifolds of the halo orbits are used for halo orbit insertion. The intermediate transfer arcs are designed using two-body Lambert’s problem. The total delta-V for the whole trajectory is computed and found to be lesser than that for the conventional trajectories. For a 480 km Earth parking orbit, the total delta-V is found to be 4.6203 km/s. Another advantage in the present approach is that delta-V does not depend upon the synodic period of Earth with respect to Mars. 相似文献